[BirdDog]

I would not even touch this unless you had a pre-purchase inspection by a Porsche dealer or a good indie Porsche shop. It sounds like this guy isn't going to let you do that. For that reason alone, you should pass on it.

Keep in mind that those things you listed are the things that you know about. There are bound to be things that you don't know about, or haven't considered. For instance, the tires. Did you check the date codes on them? It's usually recommended to change the water pump every so often. Has that been done? AOS? Brake fluid? Are those the original 21 year old struts? Brake pads?
He's only owned the car for 2 years? Does he have the complete maintenance records from previous owners?

This is why you need a PPI. A CarFax would be a good idea too (to check for accidents, flood damage, etc).

As rexcramer said, for $12K you can get a nice clean, well cared for one. You'll be spending at least that much just to get the known problems fixed on this one.

Not trying to rain on your parade, but I want you to go in with your eyes wide open. As the old saying goes, "there's nothing more expensive than a cheap Porsche."