Heh, I was in your exact position, Vinecnt's Inferno, around three or four years ago. I ultimately ended up selling my gamecube and buying a PS2, and I have only regretted the move when a few games came out that would never port to he PS2 (Metroid Prime: Echoes namely). However, luckily for me, I sold my Cube to a friend close to me, Aralith in fact, and was able to play Super Smash Bros. Melee and Metroid Prime and the like whenever I wished.

Basically, if you are done with your games and have been left wanting stuff from the PS2 more and more, than by all means, trade your Cube in and get a PS2.

Just have a friend you can bum a Cube off of for when the "need" strikes.