As a dealer, I only buy cars that I can inspect myself.
As a second choice, I would use a Porsche dealer to inspect the car before I pull the trigger.
Still, since there are so many Boxes around, why take the risk.
Now, if we are talking a new car, that is certainly a different story.
BTW-the vast majority of Porsches listed on EBAY do not sell over EBAY. That should tell you something, no?