If you're in the market for a cheap phone with power to spare, there's an LG G3 with your name on it. Well, it's really best if you're outside the US, but do you really need LTE? At $399.99, the international G3 is a solid deal and $80 less than last time.
This is the D855, which has LTE bands for non-US markets—700/800/900/1800/2100/2300/2600. No, that 700MHz band isn't the same one AT&T uses. You will still be able to get HSPA+ in the US on AT&T and in re-farmed T-Mobile markets. Also note, this isn't the same G3 you can get in the US. It has a 5.5-inch QHD screen and Snapdragon 801 like the US version, but the international device only has 16GB of storage and 2GB of RAM. It comes in gray/black or white.
Shipping is free in the US and tax is only paid in Missouri. If you're shipping elsewhere, the fee is higher but not obscene (ex. $29 to Australia). You might have import charges in some countries, though.