The T-Mobile Lumia 521 is essentially the Nokia Lumia 520 with the usual North America mobile operator branding for exclusivity. The Windows Phone has been rather difficult to locate, particularly at Walmart stores. The device has appeared on SlickDeals and we've looked around the Walmart online store at various locations to confirm that there's stock available, depending on your location.
The Lumia 521 is exclusively available on T-Mobile and can be picked up for just $130 pre-paid. That's not a bad deal at all.
We've previously looked at Nokia's cheapest Lumia Windows Phone (along with the Lumia 520), so do have a read through our thorough Lumia 521 review. Be sure to head on over to your local Walmart, or check online to see where you can pick up a Lumia 521.