There are a couple of Pelican Articles that I think are must reads when anyone is considering buying a cheap... ah... affordable porsche. As always, remember to get a PPI on the car, before you buy it. You don't want to find out about "hidden" cost later on.
check out these articles:
911 FAQ Version 2.2
Affordable Porsches - Can You Really Buy a Porsche for $10,000?