hi, i'm about to go check out a 1991 735i tomorrow which has 185k mile on it with the owner asking $2500. ITS ABSOLUTELY CLEAN and i mean freaking clean to the smallest details...its automatic with black color. The guy has about 4 cars with this BMW and he's rich.
-I just want to know if the price is good at what he's asking?
If not what price should I offer him?

Sounds fantastic!

I would love to find a great deal like that.

i may buy it, lol

;)

if it passes a PrePurchase Inspection which will give it a clean bill of health (e.g. tranny, engine, tires, bakes, electricals, etc.)...then GIT R DONE!!

The usual checks like service records, CARFAX, VIN service history check also helps, of course. Also run the year-make-model on ebay, autotrader, ebay, etc. and see what price ranges you get for your zip code.

I would go for it.

Ok thx guyz
Also what should I begin the negotiation on price at?

check what the median price is for local/national market (good reference is autotrader.com). Then stay as close to it (or lower) as possible.
http://www.autotrader.com/fyc/index.jsp?&end_year=2007&make2=&address=92592&start_year=2000&fuel=Gasoline&certified=&search_type=both&max_mileage=&body_code=16&drive=&min_price=0&distance=300&engine=&body_style=SUV&transmission=Automatic&bkms=1160289729041&make=ROV&style_flag=2&doors=&advanced=y&max_price=70000&model=&color=