If the 2002 is a dream car and something you've always wanted to own, then do it. The B7 RS4 was a dream car of ours and regardless of the issues that come with Audi's we purchased it. We have put A LOT of our time, money and efforts into fixing things, but it's worth it. Just be sure that you're savvy enough to do repairs when needed and thankfully you have us as a parts supplier to help with costs on parts.
We do have a 2002 tech library here:
BMW 2002 (1966-1976) Technical Articles - Pelican Parts. It's not extensive, but there are some things that can help in there. Also, if you have to tackle jobs yourself that aren't listed in the library, we offer 10% off your next parts order if you submit your own articles here:
Enthusiast Tech Article Submissions - Pelican Parts.
Good luck with your future purchase!