I agree, I'm never so desperate to play a game that I must have it on release day. Especially when someone will be selling it at a much reduced price only days after launch - often on the same day (I bought Bioshock at Morrisons on release day for £23)
That pretty much explains why I don't shop at Game.
I rarely buy second hand games, but I'm changing; slowly.
I bought Crysis 2 second hand for £19, played and completed it, and sold it for £17 a few days later. Yeah, it cost me a quid to post it but playing it to completion for £3 was more than acceptable. It's just a shame you can't do that with Steam titles.