The T-Mobile page says that the Nexus 4 suggested retail price is $499.
http://www.t-mobile.com/shop/Phones/cell-phone-detail.aspx?cell-phone=Google-Nexus-4
The only other place in the world that is selling this phone, Google, who made it, sell it for $349.
https://play.google.com/store/devices/details?id=nexus_4_16gb
T-Mobile is inflating the price by $150 in order to make it look like they are giving you a $300 discount, when in fact it is only a $150 discount.
How exactly did T-Mobile arrive at a $499 MSRP for a phone that its own maker sells for $349?