The Lumia 900 costs only $100 with a 2-year contract and is currently free temporarily because of a data error. iSuppli calculated the numbers on how much it costs to build the Lumia 900. It turns out that it costs $217 to build and manufacture the Lumia 900 and $188 to build the iPhone 4S 16GB model. The iPhone 4S retails for $200 with a 2-year contract. The Lumia 900 has a physically large screen, but has a much lower pixel density than the iPhone 4S Retina Display.