This guy's right with his final point, that Bradford can still revert to his St. Louis stats. Kelly is a QB whisperer though, so I think the odds of that aren't high. The author also breaks down the cost for Bradford:
Ideally, Kelly’s plan with Bradford was to break the cycle altogether, to steal a quarterback who was actually worthy of going no. 1 overall but hadn’t shown it because he’d never been given the chance. Looking at the NFL’s traditional draft value chart, the projected picks and Foles (the 88th pick) come out to about 600 points — equivalent to a late first-round pick. The deal essentially allowed Kelly to take a player of Bradford’s pedigree with the 28th pick, something he never would have been able to do five years ago.
Linc ....

I thought the Eagles only gave the Rams Foles and their 2016 #2. Marino was taken #27, Rogers was taken #24, Brees #32.

This is a pretty interesting article. If Bradford can be the surgeon he was against the Pack Kelly will look like a genius.