Trade in old PS3 for a new one?

i have one of the old 37 gig ps3's and its starting to get extremely slow and it has barely any memory left on it, i was wondering if i could trade it in along with a few games and get either a free 160 gig one or maybe only have to pay like 50 bucks for the new one. Can i do this? I was thinking of taking it into either Best Buy or EB games (Gamestop)