Which are basically the same than those you mentioned, ie the seller ( professional, or not professional ) and the price.
I had zero informations on these criterions from Antiquorum in their different emails and answers, not the least justification. So, at this moment, I don't know if the seller is a bona fide purchaser. I would be very interested to know how much he paid, as the winning auction was 40 K USD! So we can imagine that if he paid 15 / 20 K USD, his bona fide can be discussed.
Now, the gentleman code or simple class code would lead the involved parties to find an amicable solution...
Best,
Nicolas