You shouldn't have problems with it fouling plugs. These modern motors especially the etec are computer controlled on fuel and oil mixture nothing like the old motors. I would get serial number and see if you can find out if any work has been done or if there are any recalls associated with it. Ishtar be able to do that on line at their web site or see if you could find a dealer who would do it for you. On pricing think I would take 10% a year off and see how that looks and try blue book and see if you can get a price. At lest that would give you a starting point.