Source: http://gizmodo.com/5992452/whats-the-best-iphone-data-plan
T-Mobile has the iPhone now. It's only a hundred bucks! There's no contract! Unlimited everything! But before you get too excited about the prospect of jumping ship for forgotten carrier, let's take a look at how exactly that its iPhone 5 data plans compare to the other big dogs.
Following is a chart that compares individual device plans across on-contract iPhone carriers like AT&T, Verizon, and Sprint, as well as unsubsidized vendors with national scope like Virgin Mobile and Walmart's Straight Talk Wireless. Everyone has their own needs, obviously, but the bottom line is that if you use a lot of data, you should definitely start looking beyond AT&T and Verizon .
Over a reasonable two-year lifespan of the iPhone 5, you're looking to spend $2,120 with Sprint versus $2,260 on T-Mobile and $1,730 on Straight Talk. How that compares to AT&T and T-Mobile depends on how much data you use, but even if you stick with just 1GB/month you're looking at $2,240 on AT&T over two years and $2,360 on Verizon.
Other considerations obviously come into play; Verizon will have better reception than AT&T, AT&T will let you do simultaneous voice and data while Verizon won't, T-Mobile doesn't have a functional LTE network yet, Sprint is... Sprint. But in terms of pure value, T-Mo made a strong case for itself today.
Or, you know, just pick up a Virgin Mobile iPhone 4S and save yourself a grand.
Additional reporting by Robert Schoon. Data plan info provided by Apple. AT&T Mobile Share costs were used for more accurate comparison with Verizon's Share Everything plans.