It happens all the time, especially with guys who are in good situations the following year at school. Jake Locker? Matt Leinart? These guys could have done it in the age of 40 to 50 million guaranteed and passed it up and those guys had better shots of going #1 overall than Barkley does this year . . . you don't think Matt Barkley wouldn't stay?
And I think it's precisely the two guys you just brought up that are why Barkley will be very tempted to jump. They did not help themselves by sticking around.