I got the $15 Pre-paid plan with 500 minutes. What about Data limits/cost/cap? Do I need a Data booster too? If so, how much does Data cost per how much if I do not? I have it so my phone will download all updates and auto-sync only to Wifi spots, but I want to know anything relating to Pre-paid plans and Data, do I have a specific amount of Data with my plan? None? Does it do the whole $7.50 pay-per-use for 50MB thing?