I have another opinion. I bought three paintings from a thrift store because I like them. When I got home I looked up the artist and found that I had bought $250-$500 paintings by a known artist for $10-$20. So what is their real worth??? A trained eye could have bought them to resell and priced them legitimately and that would not be “wrong” since they are worth the higher $’s. The “price” is in the eye, knowledge, and negotiations of the buyer and the seller.
No one has an obligation to sell something for less than it is worth just because they recognized and took advantage of a bargain. Brass is worth good money even at the metal recycling right now, apart from the artistic value. And no one would complain if the antique store had bought them as $200 brass swans but had to sell them for $10 because they found out the swans were only brass plated.
I find that art is hard to sell. Unless it is Hunters. So many art, doesn’t really sell. Unless it is the one. Kinda like metaldecting. In the end Some one has to want it.