Should I buy it??
 

I came across a 1978 300D, it has been sitting for a long time but its a one owner car, not sure on the mileage yet but its in pretty decent shape. They said it ran when they last drove it but the owner had a stroke and no longer drives. They are asking $800 I do need a parts car but am I better off getting it running and selling it?

Pretty decent shape isn't a good enough description to give an opinion. If its really nice with low miles, then it may be worth it go get running and sell. Its not going to bring the sky high ebay prices because its not a Turbo. Not to mention the evil servo.

it is rust free, My DD is a 1984 300D turbo, Is it too much to be a parts car for mine?

Its not going to have many compatible mechanical parts for your car to warrant keeping it.

Cool, thanks for the info, you just saved me $800 :)

my 77 was sitting for a year or so but I bought it since I had parted out a 81 300D and had many parts for it. As for the evil servo you can get around it by converting toi manual climate control.

Although I agree with Tyler in that I don't think it is a good option as a parts car for you, for $800 a 300D in decent shape and low miles is a good deal! Chances are you would get it running without too much trouble if it was running before it was parked.

I bought a 240D in a similar situation for $400 (worked when it was parked then wouldn't start) and all it needed was a primer pump.