Wow, I went in yesterday to do some trades and was pleasantly surprised. Some of the games I traded in gave me more value than I paid for years ago. I traded about 26 games and walked out with $270 worth of credit (that's including the promotions). The newest game in the batch was left 4 Dead 2 which added over $25 credit (again, that's with the bonuses included).
And of course thanks to CAG and SD, I never paid full price for those games to begin with >< I was just hoping to get more than a buck or two for each one.
Are you intending to list the base prices for the games you traded in so that they can be updated in the OP?