...to what the car's worth to you. My experience: I picked up an 83 633CSi in Arizona in near mint original condition and only minor sun fade on the rear trunk lid. It probably had rarely seen rain, let alone snow. The mileage was at 89,000 and the price paid was $6000. It did also have LSD, and functional AC, new driveshaft, etc... I probably paid too much, but I'd do it again-that's the clincher. Out here in Vermont the same car, from here, would be near half that amount. That's where the relative part comes in. So my answer is that there really isn't a definitive one, but given the condition and that it is a CA car, you might expect to pay roughly $5000. I do like the 83-84 model years for their simplicity in terms of options, but performance parts are more readily avaiable for the later models. That's an additional consideration depending upon whether you're a purist. Also, I prefer a 5-speed as I have a 535ia which seems docile in comparison to my coupe. Good luck and regards, Chris