Originally Posted by Robin-535im
For an ordinary M30 I'd say the mileage is okay, but seeing as how the S38 engine is a pricey rebuild, I'd say 12k is too high. For that price you can get one with half the mileage, and although mileage is not an absolute indicator of health it's a good first order estimate. I saw one on roadfly classifieds for 13k with 102k miles, which is probably about right.
I've also heard that the trannies can go on the e34 m5 if not properly maintained, so service records would be critical before buying it with that high of mileage. Offer the guy $8k if you love the car and it passes pre-inspection, otherwise I would keep looking.
HTH
Robin