Last week, a tweet from T-Mobile revealed that the carrier would release the Microsoft Lumia 640 on July 16th . But the phone might turn out to be available well before that date. A picture shows that the T-Mobile branded version of the handset is now available from discount retailer Walmart. One particular New York based store (this one is located in Rochester) is selling the phone for $99.76. That is lower than the $129.99 that pre-paid carrier Cricket is asking for the model The Microsoft Lumia 640 comes equipped with a 5-inch, 720 x 1280 resolution screen. That combination produces a pixel density of 294ppi. Under the hood is the Snapdragon 400 SoC, which contains a quad-core 1.2GHz CPU and the Adreno 305 GPU. 1GB of RAM is aboard with 8GB of native storage. For those needing additional memory, there is a 128GB capacity microSD slot available. An 8MP camera adorns the back of the unit while a .9MP front-facing camera is ready to handle selfies. A 2500mAh battery keeps the lights on, and Windows Phone 8.1 is pre-installed.This particular Walmart had received two Lumia 640 units, both of which sold out quickly. This bodes well for sales of the handset once it is officially launched by T-Mobile.source: WMPoweruser