I bought an '88 M3 with 109,000 on the clock for 9K. The car is in great shape, only upgrades were JC Chip, front strut brace. Don't even bother with the KBB or NADA. You just have to look at alot of cars and drive them. Find a good BMW Mechanic that you can trust (preferably private shop, not dealer) and have them look at all of the cars you can get to him. I drove a '90 with a verified 42,000mi on it, and it was the biggest POS I have ever seen. Talk to some owners, better yet find an owner on an E30 ///M and make friends, they love to look at other ///M's and talk about them.