I don't hang on this forum much, but these guys are definitely the experts.
My E30 is super clean, even with 138K miles, and performs flawlessly. The previous owner handed me a two pound stack of maintenance records, and the car has been great, though I did spend some money and a lot of time removing tints and detailing the paint(Alpineweiss). I could sell it for a $4500 profit right now, and I only bought it less than a year ago (i did get a good but not great deal).
NOW IS THE TIME!!! Sounds like you have a good income, so do it!! I have a Ferrari 355, and per dollar spent I have more fun in the M3. Not only that, but there are like a hundred 355's for sale out there, and only 15-20
E30 M3's. Seriously, do it NOW, next year the prices will be ridiculous, and these cars are obviously rare. There is a dealer called Enthusiast Auto on autotrader that has 6-7 E30 M3's for sale right now, asking a lot for all of them, one is over 25K if i remember correctly!
Unlike any other car I've owned, when you do find someone who is a true fan, they are always a rabid fan, and will do anything to let you know your car is da bomb, including pedalling their bicycle 8 blocks out of their way to catch up to me. true story, and if I didn't care about boring everyone into oblivion I would tell you a dozen more. Good luck!!