Do you think I should reserve GTA IV or just wait, will it really be sold out fast?

Just wondering, I don't really like reserving it because I'm just that forgetful, I keep hearing all this hype about sell outs but I'm thinking it's just sales pitch. Also which stores are usually the cheapest. Blockbuster is usually highest but they had been the lowest w/ Super Smash Bros so I'm just wondering. THANKS in advance!!!