Exactly like what Tay has said.
1. Price will vary honestly. You might be able to find quite a difference between two units you're sampling from the same year. These could vary in price because of how well maintained the cars are and generally the mileage. Mileage is not everything at times. Engine condition being the most crucial imo, followed by whether it's genuinely accident free (chasis bengkok cases are not uncommon). I'd say a well maintained E36 328 1997 would be approx 80K+ (below 85K definitely). Also, some of these cars might carry additional accessories as well. I personally think that replica accs. don't carry any value at all so don't be too concerned about those (yet! hahah). On the other hand, there might be stuff that could add a little extra value to the car and save you some $, like newly reupholstered leather seats or a new tint or even a new coat of paint. Stuff like new absorbers/shocks/tires would probably be something to consider as those will set you back easily a few grand.
2. Depreciation will reach a base cap, after which, I'm guessing (for the model you're referring to) is approx 4-6K per year. BMWs hold thier prices better compared to some other contis like, say, Audis, but not as well as the 3 pointed star
If you're talking about the M52B28, the demand is not as high due to the higher road taxe, thus you'd notice that a M43 318 of the same year to go for approx the same price, and maybe slightly higher even.
3. Engine is my personal concern. If you're going for the 6 pot, compression checks are not usually carried out, but do this if possible. Gearbox is another nightmarish problem, that I hope no forummers here need to go through. Depending on the (genuine) mileage, the box might be due for an overhaul (costing about hmm... 3K?). Other regular wear and tear parts include, control arms, bushings and mounting, seals and gaskets, absorber conditions, tires, sensors etc. Note that wiring problems, though unlikely, is potentially another nightmare and because there are lack of wiring experts for the BMW, you could end up with another headache.
Good luck in your search.
Edit:
TRY THIS
