Ben McLemore (probably the most concerning comparison)
Xavier Henry
Noah Vonleh
Jahlil Okafor (already mentioned)
Brandon Knight
Josh Selby
McLemore got four seasons with his original team, starting a majority of the games. He has been on three teams and is still in the league. I'd say he's gotten time to develop and plenty of second chances and SAC was very patient with him. He just isn't very good. He's still made $28m in his career. The horror. FWIW I thought he was horribly overrated at Kansas and I think Bouk is a much better prospect.
Vonleh has played for seven teams. That's a second chance or two. He stinks, yet teams keep giving him chances.
Okafor has been on four teams, aka second chances. He just got screwed by being born 20 years too late. He could have stayed at Duke for 4 years and it wouldn't have changed that.
Brandon Knight made $80m before injuries derailed his career.
Josh Selby sucked and everyone knew it. He was a 2nd rounder for a reason. Xavier Henry also simply sucked. Staying in college wouldn't have changed that.
It all boils down to this...
1) You suck and everyone is going to find out eventually. At least you've fooled some teams for now. You might as well try to make $10m before the cat is out of the bag. That's a nice head start before heading overseas.
2) You were born in the wrong era. No amount of time in college would have changed that.
3) Don't draft Kansas guards.
There are guys who cost themselves money by returning. Jared Sullinger was a Top 5 pick, returned for his sophomore year, got fat and hurt his back and fell to the 20s.
Big Baby Davis was a media darling with lottery buzz after LSU's FF run but returned and fell to the 2nd round.
Perry Jones III had a cult following and Top 10 buzz. He went late first. Who knows where he would have gone if he left after his freshman year. Turns out he sucked, didn't last in the league.