"I won't buy from ebay if the price break doesn't cover the risk factor."

EXACTLY.

I often find great deals on items that I know have problems that are easy to fix, but that will scare away many potential bidders. It is very common for old LF lenses to have sticky shutters, for instance, but as long as the cosmetic condition is such that it doesn't suggest the lens has been abused, you can figure about $80 for a CLA from S. K. Grimes, and in the end, you will often have a better lens in a better shutter for less money than if you had bought it in an ostensibly working shutter that hasn't had a recent CLA, or one from a shop that may offer a guarantee, but doesn't have a repair service as good as S. K. Grimes to back it up.