Today I have 4 Iphones on the 10gb data plan. Cost is $160 per month. Three phones are past the two year contract date. I went to ATT and did upgrade and got this: Buy It : $750 Next for 20 Months: $ 37.50 or $750 total Next for 24 Months : $31.25 or $750 total Contract : $300 Assuming I have no problem sticking with ATT or contracts, what other charges will I have. AGAIN - I have no problem with a contract. I am not switching carriers.