This is probably going to be an unpopular opinion, but after all the years of being here and all the shenanigans, I honestly feel like buyers should just do whatever due diligence they are going to do, and either buy or don't buy. What the other guy paid for his copy should have no bearing on anything.
If every error of omission leads to the villagers lighting the torches, where does it all end? Doesn't the buyer either want it at the price, or he doesn't? Doesn't the buyer bear some responsibility to check the public data?
I'm not talking about fraud or active misleading. Just not being "comprehensive" in your info.
Don't mind me, it's beautiful weather, but taxes have me . . .