I didn't know this, but just found out the other day that gamefly sells games used*.
I got that new Avengers game only because it was like over half off. Instead of $60. No way in hell was I paying full price for it anyway.
Also got Mafia 1 remake for $25, and both games came in pristine condition just without the plastic wrap.
Check out games for sale on gamefly, some of the deals are great.