Third party vouches from "trusted" members or people with many posts mean shit to me and so should to everyone else. The transaction is between you and the seller not with an unrelated third party who could be collaborating with the scammer for all you know. Live and learn.
You're basically saying that a good and trusted user can't refer another user to someone else which is dumb. If I got a good deal on a car at a used car lot, I'd refer people to that dealer so that they might get the same deal or a similar deal. This situation's no different.