How much Gamestop store credit would I get for these consoles/games?

I have all of this to trade in:

Xbox 360 Elite (Black one)

Assassin's Creed 2

Batman Arkham Asylum

Battlefield: Bad Company

Borderlands

Dragon Age: Origins

Halo 3

Just Cause 2

Elder Scrolls IV: Oblivion

Mass Effect

Red Dead Redemption

The Saboteur

Skate 2



I also have a Wii that I NEVER play, so I'll probably trade that in, too. I have these games for the Wii:

Mario Kart Wii

Super Smash Bros. Brawl

Wii Music

New Super Mario Bros. Wii

Wii Sports Resort

Wii Play



I'm planning on getting a PS3 (120Gb slim) after trading all that in. Will I have to pay much of a difference?How much Gamestop store credit would I get for these consoles/games?
Tough, easily a few hundred bucks. You shouldn't have to pay a difference Bring 100$ just in case. Although you shouldn't need it, that'll get you MAG and another good game.