Following up to my "many questions" posting...
The 88 M30 M3 with 87K miles was inspected today by a BMW dealer. They told me the car was solid and staight with good transmission, engine and clutch. They did not do a compression check (didn't have a compression tester to fit down that small hole) but insisted it didn't need one based on the way it drove. The car does need the following: all belts, transmission mounts, both oil pan gaskets, hood shock, new differential, rear shocks, splash pan missing, R control arm (L appeared "new"), fix crack in exhaust pipe near catalytic converter, new tires, fix A/C (no freon; didn't diagnose system). I asked them the cost for them do do all the work with new BMW parts and they quoted $3400-- not including tires or A/C since the diagnosis is unknown at this time). Grand total might be $5000. They insisted the car was above average and very much worth fixing. The owner wanted $13,500 but is "very willing" to negociate. The dealer suggested $12,500 but that sounds high to me.
My alternative is an '88 M3 with 113,000 miles which is "perfect". The owner insists I can take it anywhere I want and it will "need nothing." It has a "blueprinted" engine which he reports is as good a new. It also has a new clutch, new shocks, mounts, sway bar links,bushings, radiator, brakes, full Borla exhaust, new front bumper and air dam (he didn't like the pits), Dinan chip. He reports it drives like new and uses no oil. He describes himself as "very anal" and fixes everything that isn't perfect. How much more is this car worth than the above one (if the above description is accurate) He is asking $14,000 and not open to much negociation.