[Exhibitman]

If you offer something for sale and you aren't legally unable to sell it (e.g., subject to a conservatorship, incompetent, a minor, etc.), you have no right to complain when someone pays your price, and the buyer doesn't owe you jack squat in extra compensation. Do. Your. Damn. Homework.

Not the same level but the same idea from the other side: I found a rare item and offered it for sale. Did my research but no comps available. I started the bid low and put in a BIN. Someone snagged it almost immediately. I did my best to figure out a price and offered it to an AH (rejected), so all I could do was pick a price and sell it, and be happy that I made a profit. If you as a seller obsess over wringing out every dollar, you will have a miserable time. What's the old investment saw, pigs get slaughtered?