OK. I can't stand it and have to say something. First, if the gun was sold a couple of years ago, that was a fair price. You know the dealer and I don't but many longtime dealers have little knowledge of certain segments of the market much as certain gunsmiths have no experience with certain guns. Keep in mind that if ethics ia a system of morals, then it should extend to all indviduals. That would mean that if we walked into a shop and and found an "O" frame VHE 16ga. in 80% condition for $600. it would be incumbent on us to inform the dealer that the 16ga. is no longer undesirable, SxS"s now have a following and that if he would raise the price by three or four hundred percent we would then buy the gun. Not.
Considering the buyers haste in purchasing, it is reasonable to assume that he felt he was taking advantage of the situation. You did precisely the correct thing by not intervening.