I personally would not buy a car, especially a Porsche on eBay. That one in particular is overpriced. You can get a good condition, clean title running 2.5L for under $10k these days.
What are your goals for the car? If you want a restoration project, Porsche parts are very, very expensive, so it probably is no the best way to go. You could spend the purchase price of the car on just the water seals.
If you want a Spec racer, then I would look for a 2.5L that runs well, since you will tear everything out anyway.
Best!
