Every wireless carrier wants you to think that it delivers the best smartphone early upgrade plan, but which carrier actually does? Re/code decided to crunch some numbers and found that ATT actually delivers the plan with the lowest price, although you could certainly argue that T-Mobile gives you the most bang for your buck. Calculating how much the average person is going to pay for a smartphone early upgrade plan is tricky, of course, because there are so many variables to consider and because carriers seem to go out of their way to make these plans more complicated than they need to be. To make things simpler, Re/code decided to compare what it would cost to upgrade to a 16GB iPhone 5s