Paper Mario Game Music Soundtrack CD(What a title) was never released in stores and the only way to obtain it was to sign-up for Nintendo Power back in 2002. Finding a copy online is rare, I remember seeing one copy a while back on ebay for $400! — which is around the amount that the Super Mario RPG Original Sound Version is going for these days. The album, as far as I know, contains every track from the game but it's been a while since I've last played through the N64 Paper Mario. So, if there's a song or two missing from this soundtrack, send us a message and I'll see if I can find it in the game files.
The composers of the soundtrack is Yuka Tsujiyoko & Taishi Senda. The release date is unknown month from 2001.