The Bulls recieve ~> peanuts

Barns is overrated role player, there is a reason why Warriors got rid of him. He wanted money that he was not worth. Derozan is better, but not by much as he is not a 3pt threat and his defence is questionable at best.
DeRozan is not better than PG, but unlike Barns, DeRozan is a starter caliber player even on a fairly good team and on a bad team he can be 1st option and 2nd option on a average team and 3rd option on a fairly good one. Barns can't be that he is 1-2 slots below if not more and his time with the Kings was very telling about that.
DeRozan best move would've been to take a big pay cut and join a team like the 76ers and be a 4th option if he wants a chip, but he clearly doesn't so it is what it is.
Paul George has higher value, because he can score 2-3 three pointers in a row and change the game in a crucial moment. Demar might score 2-3 two pointers which definetely doesn't have the same impact, not to mention size, defence, spacing, decision making, IQ, passing and etc.
Derozan and PG are not comparable no matter what the stats look like - they played on far different teams having different roles. Individually and as a team player PG is far better and him getting 4yr 212m being injury prone 34yr old player who is questionable at best in the playoffs shows that very clearly.