calls and 2GB DataPlan be with T-Mobile? I currently own an iPhone 4 and have an active contract with AT&T. I have the Viva Mexico Family Talk 700 Rate Plan and the Data Pro which includes 2GB of internet usage a month. I am currently paying $80.11 a month for this line and am considering changing to a more affordable cell phone company. How much would my monthly bill be if I were to change to T-Mobile and opted for a similar "Viva Mexico Plan" and Data Usage plan with T-Mobile?