A price of $49.99 (£30.74), especially with free delivery included, is excellent value for money and is the lowest we've seen for Nokia's entry level Lumia device in any market.
The GoPhone devices are locked to AT&T, but do not require any kind of contract or obligation over and above the purchase price, making them ideal for use as a back-up phone, or as stand-alone device (e.g. music player, GPS navigator). For cellular connectivity they can be used with any AT&T SIM and can also be used with a number of US MVNOs that use AT&T as their underlying service provider (e.g. H20 Wireless, AirVoice, Aio Wireless).
As we've noted previously the low cost of the Lumia 520 is partly the result of careful specification cutting:
The low cost of the Lumia 520, in contrast to other Lumia devices, is achieved, in part, by cutting a few corners, the most notable of which are the downgrading of the screen quality and the absence of front facing camera, compass sensor, NFC chipset, and camera LED flash hardware. The hardware omissions do have an impact (e.g. compass functionality HERE Maps, video calling in Skype), but do not seriously degrade the overall Windows Phone experience.
Even allowing for the cuts it hard to argue that the Lumia 520, at $49.99, is anything other than the best value smartphone on the market. You will be able to find Android devices at a cheaper price point, but they are unlikely to be able to match the Lumia 520's ease of use and all round experience.
Here's the conclusion to our Nokia Lumia 520 review:
Taken holistically, though, the Lumia 520 is still cracking value for money, in terms of the future proof operating system, the built-in Office suite, the mapping and navigation services, the 150,000 third party applications available in the Windows Phone Store, and (as highlighted above) even the built-in camera.
The more Nokia push Windows Phone down into this price territory, the better it will do, I suspect - budget Android phones tend to be slow and clunky, whereas the 520, on the whole, flies. And with greater sales at the budget end will come marketshare increase and revenue, increasing awareness further up the price spectrum. Assuming that Windows Phone continues to grow, I suspect we'll be looking back in a year's time and realising just how much the Lumia 520 and 620 had to do with the ecosystem taking off across the world.