Is it this one being re-sold?
http://986forum.com/forums/general-discussions/64341-soul-searching.html
http://986forum.com/forums/general-discussions/65088-parting-out-my-car.html
It was on CL for quite a while, but I haven't seen it for a couple months now. I'd probably offer quite a bit less and plan to put another engine in.
Regardless of if it's that car, I'd expect that the seller is presenting the most positive info he can get away with. Still it is possible it could be a broken/disconnected wire or a bad sensor. How would you feel to get it home and find out the engine is only good for scrap? At the right price, I could be fine with that.