looking at buying a 1982 300td

[runnin262]

Help...I have been wanting to buy a 300td wagon with the intention of going bio/vo. I have found a 1982 that is almost perfect exterior/interior with 135K...a super clean car. I have driven the car a few times and the thing that scares me is that on take off I feel like a sitting duck as it takes time to get going. There is also a rather large fluid spot under the car at the car lot. I want the car but this will be my first diesel and I have heard that if the engine is bad I can expect 3-4 times the value of the car in repairs. I have taken the car to the shop which has worked on it and they say the previous owner was a maniac for detail. I am planning on taking the car back to this shop for a compression test but I live in a small town in southern Utah and this is about the only shop able to work on MB.
Thoughts please...