The 5 rules for buying games:
#1 - Have cash ready.
#2 - Don't ask the seller a bunch of pointless questions about the game they are selling.
#3 - Tell the seller you can pick up the game now. Not tomorrow, not later today...NOW.
#4 - Don't power on the game when you arrive. Hand over the money, load the game, and leave.
#5 - Don't contact the seller after you buy the game. Once you buy the game, it's yours and everything that comes with it.
Happy game hunting!