Well if you know the car history well (what I assume you do) and if you take the $9,500 and keep the car, that money buys a lot of parts at any good Porsche dismantler! I am sure you can get new seats, carpet and everything else way under that amount. You can probably replace the clutch, RMS, IMS all with that money.
Seriously, I would really check what the dismantlers have and if you can fix it yourself for way less than what you are getting, I would probably keep the car (assuming again that you know the car is mechanically sound, etc).
CR