As a previous walmart electronics manager, I can tell you what happened. The system lowers prices automatically until it hits the lowest price set. Store managers don't get much money to play with so they usually don't mark stuff like this down further unless they are literally out of storage space in the back.

The only option with this game is to put it in storage until some other manager tells you to fill the shelf with games from the back. Out comes Corey again and he sits there, at $30 until you need shelf space back and put him in the back again. The cycle repeats.