If you haven't spent that money, I'd wait until around Wednesday of next week to buy the games. By then, Gamestop will have a bunch of games sold to them from kids who didn't want it. You'll be able to pick up practically new games from much cheaper than if you went to the store.
Also, Best Buy and Gamestop will have a bunch of returns, so they'll be having an after Christmas sale to clear some shelf space.