Woo, I got stuff without spending much moneys.
First off, I traded in a TON OF SHIT that I wasn't using at GameStop and wound up with $130 (edit) $172 worth of trade-in credit. I bought a used copy of Mass Effect (which automagically got me a GameStop card slash magazine subscription renewal) and a wireless Cock Band guitar, leaving me with $65.
Next, I traded in my Xbox 360 racing wheel to a small game store in Aliquippa, PA, called the Gamemaster's Realm. I only got $35 of store credit from it, but that's okay since nobody else takes racing wheels. Anyhoo, I started putting the next part of my Master Plan(TM) into play by purchasing Guitar Hero 3 from them. I also bought a copy of Sonic & Knuckles -- since I wasn't able to find it at any other place up until that point -- and picked up a second PC->GameBoy cable (it comes with the GB/GBC GameShark yet I've never actually used it with my GameShark...kekeke I'm awesome).
Then, I went back to GameStop and bought an Xbox 360 Guitar Hero guitar and a copy of Guitar Hero 2 -- both used -- for $62. FUCK YEAH.
Long story short: I traded in a whole bunch of shit that I'm not going to miss, wound up replacing my second shitty Rock Band guitar with a new wireless one, got rid of the awful first-generation Guitar Hero PS2 controller I had (that was part of my first trade-in set, along with GH1 and GH2), effectively switched my Guitar Hero stuff over from PS2 to Xbox 360, and picked up Guitar Hero 3 at the same time.
Damn, that wasn't short at all. OH WELL.
Pardon my hyperness, I'm coming down from a Monster and a 1L bottle of Vault. YAY.
Edit: Interesting note: Guitar Hero 1 for PS2 nets you $9. Guitar Hero 2 for PS2 only gets you $8. Interesting.