I have read some forums that although you have the option to pay full price from Best Buy for the current Iphone lineup, actually more than retail in some cases, the phones are unactivated and inserting any sim in them after purchase locks them to that particular carrier whether it be AT&T, Sprint or Verizon, there are no options for Tmobile, or other carriers that make use of an unlocked phone. I have a $500 best Buy gift card and would rather use that on a new Iphone for family member than pay Apple cash. Does anybody have any experience with Best Buy and being able to to get their phones unlocked after they paid more than full price and use them with TMobile? Any help would be appreciated