GameCube hacking

I would really like to try my hand at homebrew GameCube development. Thing is, I need to get a hold of a copy of a specific game to do this, Phantasy Star Online I & II. Obviously it needs to be the GameCube version and I don't think the "Plus" version will work. If my readers could look out for a cheap copy of it, I would appreciate it.



Box art to the game I am looking for. Note the white background.