The iPhone with a two-year contract on AT&T, for example, costs $200 for the handset and then upward of $90 a month for the plan; over two years, including the cost of the phone, customers pay at least $2,360. With a prepaid plan on Virgin Mobile, which is owned by Sprint, the iPhone costs $650 for the handset, and then $30 a month, including unlimited data (the type of data plan that people are happier with, according to J.D. Power). Over two years, that would cost about $1,370.