If you were to buy the phone at T-Mobile with the Value plan, you would be paying full price for the device by making a down payment of $99.99 and paying the balance off in 24 months with $20 monthly installments. Best Buy is planning on eventually offering the Value plan and its pricing to its own customers. At this point though, T-Mobile has said that it is too difficult to ask national retailers to keep track of inventory and commissions like T-Mobile does in its own stores.
The T-Mobile version of the HTC One offers 32GB of native storage while AT&T has the exclusive on the 64GB model in the U.S. The HTC One does not offer a microSD slot which is why the device is offered with no less than 32GB of native memory.
source: BestBuy via TmoNews