Newbie here: What is a fair price for an '81 300 turbo diesel w/190,000 miles

[Hsolo]

Hello MB fans,

As the subject states I'm trying to find out what fair market value of an '81 300 TD. I hope I've posted in the correct forum, if not please redirect me.

Some more info about the car: It is the wagon variant, it was originally a California car (pertinent as it has been in eastern Canada for 3 years) the car is rust free and straight as a pin with no prior accidents, the paint is dull (I feel a good buff could bring it back), water is slowly leaking in from somewhere though all the rubber looks good to me, has had a GreaseCar veggie system installed, was being driven daily until about two years ago when it was parked outside, last winter (I believe) it had to be moved to avoid the snowplow drivers rath and was difficult to start at which point a helpful neighbor suggested starting fluid (not good I know) which was used liberally until it fired up and the car was moved to a safer local, it is currently a non runner.

The owner is an old friend of mine who I was visiting for the first time in ages. He mentioned the car and that he was looking to sell but that it wasn't starting. My limited mechanical background/hobby is with the early water-cooled vw's and having just gotten a 1.6d (my first diesel) rabbit up and running I offered to take a look. The troubleshooting began by pulling a glowplug and putting 12v to it, it remained ice cold, at which point I read the back of the starting fluid can and saw the warning not to use with automatic glow plugs. The plugs are ruined in my reckoning. The starter turns over slowly even when attempting to jumpstart, and when pulling a return line for better access to the plug it was dry and there was no evidence of flow in the supply to the ip. This is as far as the troubleshooting went. I'm concerned that there has been gelling of the veggie oil or dirt from the veggie that has plugged up the fuel system. Although he has told me that there is a diesel purge built in to the controls that should flush the system before shutdown. Before I suggest to him that the pump should be stripped down, cleaned and rebuilt then following that injectors pressure tested and possibly rebuilt I hoping that those with veggie running experience could provide input.

Finally with all of the above in mind what would you offer for the car, keeping in mind that I don't want to lowball him as he is a close friend.

Thanks for reading. All and any input with fair price and further troubleshooting will be greatly appreciated.

Nat