It really is worth it and you can probably pick it up for a small price since it's an "older" game. The story for FO1 is much better and the atmosphere is a lot darker. You don't get so many weapons to play with and the NPCs aren't that good, but that shouldn't stop you from buying it.
Music, design, graphics... It is a masterpiece, and although playing the original first, then the sequel should be a general rule for everybody, it is worth playing. Unless, of course, you first read all strategy guides and reviews trying to decide is it worth your time... Especially strategy guides, because they give you the idea of game's structure.
Fallout one is what made fallout 2 so great.
you can't get Fallout two unless you have plaed fallout one. I mean you wont get certain parts of the game unless you have played fallout 1 aka Millitary Base, N.C.R