I'm going through a similar experience now
I sold a large format lens (second last one...), it had been dropped on a rock and had some damage, but the (professional) photographer from whom I purchased it told me it had been checked on a collimator and was optically fine. I said all of this in the listing. I had never used the lens, I just wrote what I was told and said that the buyer has 14 days to test it and I'll give a refund if not satisfactory. So I got a message from the buyer in Germany saying that the Copal 0 shutter is "desequilibrated by 0.2mm". I said I didn't know what that meant (I still don't) but I'm sorry, please send it back to me and I will give you a full refund. The response: "not acceptable". What? Since when is a full refund "not acceptable"? Well, because he had paid import duty on the lens, he didn't want to return the lens, but instead wants me to pay for an expensive repair. (Or rather, for what he claims will be an expensive repair.) To top it off, he says the lens has scratches (on the outside, not on the glass) that were "not disclosed" and therefore the lens is not "as stated." OK, firstly, who buys a lens that was dropped on a rock and then worries about a few minor scratches, secondly, I didn't say anything in the listing about whether or not there were scratches other than the DENTS caused by the drop, and thirdly, the only scratch I could discern in the iPhone photos he sent me is clearly visible in one of the photos in the listing!
I then offered to replace the "desequilibrated" Copal 0 shutter, if he sends it back to me. I have one last LF lens and I can send him the shutter from that. Silence. No response to this bend-over-backwards offer to a buyer who thinks that a full refund is "not acceptable."
I have this awful feeling I'm about to be ripped off several hundred dollars. Could be up to six months before it happens. I guess I'll find out.
Thanks for reading, I had to get that off my chest
