The upshot of this is caveat emptor. Don't go bidding on anything about which you lack knowledge. If you have doubts don't bid until they are satisfied.
Yeah, you're so right, what good is the (seller) legend of an old pipe that I can only parrot for their personal revaluation, without even having any proof. With pipes of which one hardly knows anything, one should believe the salesman actually first of all nothing. But I also like dealers who do not know when they sell a high-quality estate pipe and it is them to get rid of their junk.