Windows Phone has been far from a rousing success so far, but that hasn’t stopped Microsoft from trying to goose sales of Windows Phone devices in any way it can. AllThingsD reports that Microsoft’s latest strategy involves pushing Nokia’s dirt-cheap Lumia 521 into Walmart and selling it for $150 off-contract. The goal is to undercut the appeal of subsidized devices such as the iPhone and the Galaxy S4, which both sell for $200 or more at most retail outlets if users sign two-year service contracts. But by offering the Lumia 521 through T-Mobile without a service agreement and at a comparatively low monthly rate of $70 for voice and data, Microsoft may have found a clever way to attract budget-conscious phone shoppers. The Lumia 521 features a 4-inch 800 x 480-pixel display, a dual-core 1GHz processor and a 5-megapixel rear camera.