ebay is loaded with people who try but do not sell their items because they have no clue as to its value. Craigslist is even worse, with many asking $100 for third party lenses bought at a garage sale for a buck, and have no idea as to what its or what camera it fits. Most of them claim it will fit any camera.
Some lady is selling a 135mm soligar lens... and I talked to her once and said that it might help if she indicates which camera brands the lens would work with & she didn't listen. With an adapter I might want it for shits and gigs, but I have no clue.