Yeah, I would want actual offers before I talked about what it was worth (if then). A friend of mine has been disposing of her parents' estate which included a lot of things like comic books and sports cards, and it's very easy for a lay person to find an example of something sort of like what they have selling for seven figures, much harder to actually sell the actual thing in their hands for that.

And if they do...they put in the work to find the right buyer etc. Brother did not. If he bought something worth 6-7 figures himself, he will probably not leave any stone unturned in his attempt to find it. "Hey, maybe I left it at the house I was staying in" will have occurred to him. If he bought something he didn't know was worth 6-7 figures and did not care to dispose of himself, he has exactly what he gets from it.