You can collect Virtual Currency the standard way which is to slowly play the game or you can cheat a little with these locker codes. Here are some useful locker codes that you might want to try out.
Those playing the NBA 2K15 can try using the codes SHOOT2MUCH500 and #2KTVPOSTSEASON to get some free locker codes. The first code will give you 500VC while the second code will give you 1000VC.
The codes #2KTVMELOGEAR, #AIRCRAFTCARRIER, RA9M5-EQZCF-2EYQQ-IF5AF-UEP51 will all give you a free in-game item. The item drop is randomized so good luck. As for those looking to play the game with an ABA ball, you can try using the code PAYRESPECT.
The same code, PAYRESPECT can also be used on the newer NBA 2K16 game to get the ABA Ball.
To use the codes, go to Main Menu > Options > Features > Locker Codes and enter the required codes.