1. The money from going in the 10-15 range is not "that much." It's not like the NFL where a 1st rd rooking contract sets you up for life.
2. What if he's not ready and turns into a bust? Returning to school and improving his game would make it more likely that he turns into a quality NBA player and gets a big pay day down the road.
3.What if there is a lockout? In that case he won't be playing nor will he get paid.
4. He's not going to have a down year. You dont suddenly go from averaging 20 ppg to being terrible especially in basketball which is largely an individual game. I haven't heard anything about next years draft being stronger and even if it is Burks should be a more attractive prospect next year having spent an extra year in college. Injury is a conern but it is highy highly unlikely that he would suffer some kind of career ending injury.
I say come back, you get to play in a new conference, use the new practice facility, enjoy college life for another year before "adulthood", get one step closer to a degree, be the big man on campus and one of the superstars in college basketabll as opposed to sitting on the end of an NBA bench, lead the team to a pac-12 title, improve your game and as a result your nba-rediness and your draft stock, and dont risk being caught in a lockout.