MobileUnlocked has put together a very cool interactive map showing the prices of the iPhone 5s in nearly every country around the world. Pricing is broken down by percentage of GDP, giving the retail cost a truer weighting to people's purchasing power in the countries. Based on GDP, the iPhone 5s is the most expensive in China, costing 9.55% of China's average GDP. The US has the cheapest iPhone cost to GDP index of just 1.55%.
Interestingly, the map goes further than GDP by allowing views to look at iPhone prices in US Dollars and British Pounds, both with and without tax. The tax option is fascinating as it shows you just how much of an iPhone's cost is due to government taxes and not the building costs and Apple's healthy margins on the device itself.
All prices used in the map were taken from the cost of the 16 GB iPhone 5s on November 18, 2013.