Where are the best places (us) to buy older (85-94) cars?

I'm talking probably along the east coast. As close to New Hampshire as possible. I'm looking to buy a super clean Honda Prelude Si. But it also has to be cheap (under 4k). Craigslist only let's you search one small area at a time, When this car isnt really super common, I see maybe 2 half way decent ones for each areas. Any insight?