The Vodafone Smart 4 Mini takes this idea to the extreme, offering you a full smartphone experience for only £50 up front. We're down in territory belonging to the £40 Nokia Asha 503 and the £70 Samsung Galaxy Young.
We've seen the competition at the lower end of the market heat up dramatically over the last couple of years and it's now eminently possible to get a handset for less than the price of a tank of petrol.
The PAYG Vodafone Smart 4 Mini is about as far from the premium HTC One M8 or Samsung Galaxy S5 as it's possible to get. It may not be up to the task of being your primary handset, but as a secondary device for emergencies or holidays, it has everything you'll need.
Of course, the Vodafone Smart 4 Mini is locked to Vodafone - so if you're in a poor reception area for the red network you might want to give it a miss.
This isn't Vodafone's first Smart handset and in terms of design, it's almost identical to last year's Vodafone Smart Mini.
The boxy black chassis means it's far from the best-looking budget mobile out there and with dimensions of 122 x 64 x 12mm it can't claim to be thin either.
However, the handset is light at 111g. Build quality is middling - there's a bit of flex on the chassis when you push down on it - but it seems robust enough to survive drops and bumps without undue damage.
There are two physical buttons on the phone. The first is the power switch located on the top of the handset next to the 3.5mm headphone jack, and the second is the volume rocker on the right hand side.
Both have a reassuringly deep click to them and, as with many Android handsets, the volume down part of the rocker can be used as a dedicated shutter button when in camera mode.
The Back, Home and Settings buttons are soft-touch keys at the bottom of the 800 x 480, 4-inch WVGA screen which is, unfortunately, surrounded by a chunky black bezel that does nothing for the aesthetic of the Smart 4 Mini.
Don't expect any high-definition visuals here, and the colour contrast is quite weak - but the welcome upshot of those limitations is that battery life remains strong.
Turn the Vodafone Smart 4 Mini over and the removable plastic back has been given a smart, light grey colour. It features the Vodafone logo as well as the camera lens and the speaker.
There's also Google's logo to denote that the phone is Google-certified and has access to the full range of Google Play apps.
It's undoubtedly a cheap plastic construction, but to give the Vodafone Smart 4 Mini its due, it sits comfortably in the palm and the 4-inch screen means you can operate it comfortably with just one hand.
As you'd expect for £50, the internal specifications are about as inspiring as the design. You're only given 4GB of internal storage to play with although Vodafone has included a microSD card slot underneath the 1400mAh battery for boosting storage.
A 1.3GHz dual-core processor is under the hood, backed with 512MB of RAM. This doesn't make for blistering performance and there's no option for 4G on this handset.
However, as I said earlier, if you're looking at this as an option for a secondary phone then the lack of muscle is a standard trade-off for the rock bottom price tag.
The key feature of the Vodafone Smart 4 Mini is clearly the price. Everything about the phone, from its specifications to its design have been engineered around keeping the cost down.
As such, screen quality, speed and storage space aren't particularly impressive. Although, conversely, the battery life is excellent.
Part of the focus in price includes Vodafone's Freedom Freebee extras that can be bought in addition to a PAYG SIM card and give you boosted connectivity for 30 days.
So, for example, spend £10 on a Freebee and you'll get 150 minutes, unlimited texts and 250MB of data for 30 days.
If you're buying your first one, then Vodafone will give you unlimited UK data for the 30 day period. Choosing one of these options in conjunction with the Smart 4 Mini – right before leaving on holiday for example – offers good value for money.
There's also no getting away from the fact this is a Vodafone handset as the company has loaded plenty of its own software onto the device.
Vodafone Discover is a news and sports feed application featuring content from the Vodafone blog while the "My Vodafone" app lets you check your usage and manage your services.
A low price naturally means a lack of certain features and chief among that is a front-facing camera. If you count selfies as a big part of your smartphone usage then this isn't the handset for you.
The rear-facing 3.2MP camera is adequate at best, but similarly, there's no flash.
Likewise, Vodafone has left out NFC and 4G in order to keep the price down, however you will find Bluetooth and GPS here.
Considering this is a £50 handset, I don't feel too aggrieved at the lack of these features.
Even the fact it runs a slightly older version of Google's OS - Android 4.2 Jelly Bean - isn't a huge issue considering the cost. That said, the recently launched Moto E comes with KitKat out fo the box.
The small amount of storage could prove an issue, given that games and large apps from the Google Play store will take up a lot of space. Thankfully, if you invest in a decent MicroSD card, this problem can be kept at bay.
Interface and performance
The Vodafone Smart 4 Mini uses Google's older Android 4.2 Jelly Bean operating system and anyone with a bit of familiarity with smartphones will have no trouble navigating around the handset.
You're given five homescreens to fill with apps and widgets which, due to the 4-inch screen size, will fill up quickly.
Similarly, typing out a text message or email with the on screen keyboard, especially in portrait mode, won't be easy for anyone with large fingers.
The Vodafone Smart 4 Mini uses the standard Android keyboard but the screen size means it's particularly compact.
As mentioned earlier, performance is reflective of the 1.3GHz processor and 512MB of RAM so when you swipe between the homescreens or enter the app drawer, it's not as fluid and quick as more expensive Android phones like the Sony Xperia Z2 or the Huawei Ascend P7.
Loading a web site over the 3G connection took a couple of seconds and rotating the screen from portrait to landscape also lags a little longer than on more powerful handsets.
Apart from the aforementioned Vodafone apps, there's also very little on the Vodafone Smart 4 Mini in terms of bloatware.
Google's Android OS hasn't been given any extra tweaks or skins although the usual Google Apps – Youtube, Drive, Google+ etc, are all here. Vodafone has preinstalled Twitter and Facebook but has otherwise left well enough alone.
One strange decision though is to include both the default Android browser and Chrome on the handset. Both programs offer tabbed browsing and the ability to import favourite sites, bookmarks and the option to save pages for offline browsing. So having them both here seems like a real waste of space.
The Vodafone Smart 4 Mini posted a GeekBench 3 score of 581, which is about standard for a dual-core processor at this level. For comparison, the recently released Blade Q Mini, which costs £60, posted a GeekBench 3 score of only 468.
The main usages for a phone at this price point are casual browsing, posting to social networking sites and the standard calling and messaging features. And, thankfully, none of these are too tricky or too demanding for the Vodafone Smart 4 Mini.
Battery life and the essentials
Tucked inside the Vodafone Smart 4 Mini is a 1400mAh Li-ion battery that actually offers up a pretty reasonable performance.
Due mostly to the lack of high-end features and the lack of an HD screen, I found that 48 hours with the Vodafone Smart 4 Mini on a single charge was within reach given moderate usage.
I used the phone to make calls, browse on both 3G and Wi-Fi and take pictures without distressing the battery too much. Charging is handled via the microUSB slot on the bottom of the handset and a small, white, notification light appears at the top of the screen to tell you that the device is charging.
Unlike the similarly-budget Sony Xperia M or the high-end Galaxy S5, there's no option to enter a "power-saver" or "economy" mode. So, if you want to conserve juice, the best option is to power down the brightness and turn off the data roaming.
You can find Android's breakdown of your battery usage in the settings menu. However, because of the small, non-HD screen, it's unlikely you'll be using the Smart 4 Mini for battery draining tasks like watching video or playing graphically demanding games.
Because the Vodafone Smart 4 Mini has a removable back, you can always pick up a replacement battery and keep it with you as a last resort if you're planning to take this phone travelling or to a festival.
If you're worried about losing power though, I'd recommend picking up one of the multitude of third-party battery packs that can be found in most electronics stores.
I ran TechRadar's battery test on the Vodafone Smart 4 Mini with full brightness and all the push notifications enabled. Over the space of 90 minutes, the test drained a 100% battery to 63% which isn't particularly good.
Battery life is a big purchase decision for most people when it comes to picking up a phone, and the Smart 4 Mini holds its own in that department as long as you keep away from movies and intensive gaming.
We'll talk about the camera in the next section, but otherwise the Smart 4 Mini offers the kind of essentials you'd be looking for in a phone at this price.
Arriving with Google certification means that you can take advantage of the massive Google Play store. As well as high profile apps like Minecraft, Plants vs Zombies, Whatsapp or Skype, you also get access to Google Movies, Books, Magazines and Videos.
These allow you to rent (or buy) a huge amount of content from Google and download it directly to the handset. The strength of a smartphone is as much about apps as it is hardware, and thanks to the Play store you can fill the Smart 4 Mini with plenty of features that it doesn't come with out of the box. Just invest in a microSD card.
Making and receiving calls is fine and I didn't experience any dropped signal during my time with the phone.
Volume on the calls isn't as loud as it could have been but it didn't get in the way of my conversations. Also, because the phone is so light, I didn't experience any trouble when holding it up to my ear for long periods of time.
The only real area the Vodafone Smart 4 Mini falls down in terms of light usage is that I found the 4-inch screen to be too small. Perhaps I've become too used to the 5-inch screens of most premium handsets but the Smart 4 Mini feels cramped during web browsing and typing out emails and messages in portrait mode can be tricky.
That said, it does have all the essential features – good battery life, microSD card, Google Play – that I would look for on a budget handset. Finally though, it does come back to the £50 price tag, which really makes the Vodafone Smart 4 Mini a bargain.
A rear-facing 3.2MP camera is all that's on offer with the Vodafone Smart 4 Mini and because there's no flash, it doesn't hold up well in low-light environments. A night mode option is available but in reality it is a poor substitute to a flash.
You won't be taking any professional-grade photos with this handset and there aren't any clever HTC One M8-style ultrapixels or advanced features here.
Instead, it's a WYSIWYG budget snapper that will suffice for quick shots on the move that can then be posted to Twitter, Facebook or Instagram.
That's not to say there aren't a couple of features to play with. You can change both the ISO and the exposure level, as well as take a Panoramic shot. GPS tagging is also on offer so you can add location tags to your snaps.
There's also the option to shoot video on the Smart 4 Mini at QCIF, VGA, 480p and 720p HD resolutions. You can choose to mute the sound recording as well if you wish.
Take a look below for some examples of shots taken with the Vodafone Smart 4 Mini.
It's hard to invest emotion in the Vodafone Smart 4 Mini in the same way as you would the HTC One M8 or iPhone 5S.
This budget handset fills a completely different need and, truth be told, fills it quite well. There's no need to sign up to a lengthy contract and because of the extremely low up-front cost, it's unlikely you'll suffer any buyer's remorse after you've bought it.
This isn't a phone you treasure and use every day, but it is a suitable alternative during a trip abroad or for a child to use as their first phone. Everything revolves around the low price tag and I think it's great to see that smartphones have become so affordable.
The price tag on the Vodafone Smart 4 Mini makes it particularly attractive, as does the decent battery life and the fact that it has full Google certification.
The addition of a microSD card slot is also a very positive inclusion because if Vodafone hadn't offered the extra space then the 4GB on-board storage would be a huge hindrance to using this phone. And, apart from Vodafone's own apps, the lack of preinstalled bloatware is also refreshing.
The design, while basic, isn't hugely off-putting and the build quality isn't bad either. The phone is light and the 4-inch screen means you can use it easily with one hand.
Unfortunately, that same 4-inch screen also means that using the keyboard and certain apps is a bit frustrating if you're used to larger screens on more premium handsets.
I also disliked the camera and the lack of a flash, although given the price point, I'm happy to overlook the omission of a front-facing camera. Nokia has shown that a budget handset doesn't have to compromise on the camera and the Finnish firm's excellent Nokia Lumia 520 is a good reminder of this.
The Vodafone Smart 4 Mini is far from the best Android handset on the market. The £50 price tag should tell you all you need to know about this phone. It offers just enough in terms of performance and features to make it a worthwhile investment as a second handset or an emergency stopgap between models.
The real difficulty lies in the fact that, if you're on a budget, there's any number of similar handsets, like the Moto E, ZTE Blade Q Mini or Samsung Galaxy Fame to choose from. Then, if you're willing to spend a little more you can get the Motorola Moto G which is better in every single way.
Ultimately then, you won't be disappointed by the Vodafone Smart 4 Mini as long as you pick it up with the full understanding of what the £50 is buying you.
If you need a spare, practically disposable, handset for making occasional calls, browsing or giving to the kids so they can check Facebook then there's nothing about the Vodafone Smart 4 Mini that should put you off.