Right. A matched set of a .357 686 and a .22 617 isn't a matched set if it's been broken up.

If only one is being offered and the other part of the set isn't part of the deal, then the single one being offered will have no value more than any other single pistol of the same model and condition.

I agree that $500 to $600 is about right for the one pistol. Any more than that and I'd pass.