12 minute quarters and let it sit in coach mode for an hour. When you come back the game will be over and you'll get 600 VC.
If you don't want to wait, play an online MyPlayer Blacktop game. You get 150 VC just for playing and it takes 10 minutes. Immediately after the game is over go to the main menu and go to the offline Blacktop and do a 1v1 match of Jason Richardson vs. Nick Young. Shoot 3's with J-Rich and don't play any D. You get 150 VC win or lose. Takes 3 to 4 minutes. Go back to online MyPlayer Blacktop and do it all over again. You'll get 300 VC for 15 minutes of your time. That translates to 1200 VC in an hour, much faster than the "coach mode" method.