Lumia 521 is the less-than-$150 Windows smartphone for T-Mobile. Walmart will start carrying the phone next week. The 521 is a T-Mobile-specific variant of the Lumia 520 that debuted at Mobile World Congress in February. It offers good-but-average hardware for the price (1 GHz dual-core processor, 4-inch touch screen, a 5-megapixel camera, 8G storage expandable to 64G).
However, the phone doesn't require a long-term contract. Walmart will sell it with T-Mobile's $30/month unlimited data and text plan