Well, it's been a year since I bought the E38 on evilbay.
I paid $7500 for the car. It had 140k miles on it at the time of purchase. It now has 158k on it. Black on black, and in excellent condition. I didn't have a chance to see it or inspect it in person before I bought it, but I asked a lot of questions, and got pictures of the instrument cluster when the car was running to se if it had the telltale arrows indicating system malfunctions. Carfax had come up clean, and the pictures of the dash said all was well when running, so I took a chance. Glad I did.
There are certain areas where these cars have known problems. There was no record of those areas being addressed, but at 140k miles, I'd have to assume that they either had been or would need it soon. Those areas are the cooling system, charging system, and some of the sensors. Luckily, those areas are cheap to deal with.
I decided to start out with that I would replace some of the cooling system for peace of mind. The radiator was $145, the expansion tank for the radiator was $45 (I bought both off of ebay, as well. The radiator was an OEM unit, but the expansion tank was aftermarket.) I also replaced both hoses. The replacement of these items took about an hour with just a pair of screwdrivers. Not long after the cooling system was upgraded it threw a code for the camshaft position sensor, and was hard to start. The CPS cost me $95 at the dealer, and took 15 minutes to change with just a torx head screw. That solved that problem.
Two months after these repairs, and I noticed a coolant leak. After searching it out, turns out the new aftermarket expansion tank had cracked and was leaking. Serves me right for not going OEM. Went to the dealership and bought a new one for $65 (BTW, I had also joined the BMW Club not long after buying the car and the club membership alows discounts at certain dealers; the one next to me gave a 20% discount on parts and service to club members!).
Last fall the battery light came on. After doing some checking, the alternator was not charging. Checking with e38.org (the best source of info for these cars) it was reported that the regulator internal to the alternator was the most likely culprit, as the brushes tend to wear out. Well, it had enough miles on it I guess. The regulator with brushes was $95 at the dealer. A few hours of labor and the alternator was repaired.
That has been it for repairs on the car. Not too shabby for a year in the life of a 150k mile BMW...
Had these repairs been done at a independant shop, you'd be looking at probably $100-1500 total over the year to have done it. But, E38.org has detailed photo writups of most major and minor repair and modification processes, and a surprisingly large number of owners do the work themselves. Most of them are, in fact, using the BMW as the first car they've done any work themselves on, and are successful. That's how easy they are to work on.
I've upgraded the lighting on it and added the M style real lip spoiler. Plans include the updated LED taillights and the factory M Parallel wheels. (I'd already have them but for the cost.) It's been a great daily driver, getting upwards of 27 mpg on the highway, and averaging around 20 mpg in the in-town commute. It handles outstanding, not just for a large car, but in comparison to cars in general. I loved taking it on Skyline Drive in the mountains of Virginia! BMW knows how to get suspension and steering right. The E38 is a stylish car still, even after all these years. Much better than it's replacement. Next goal, 200k miles!