I believe that Outlaw established the ban on selling equipment (Outlaw or otherwise) in the forum due to liability concerns. You and I might never think of suing Outlaw because a forum member ripped us off in a transaction that took place through the Saloon, but some people would take such an action and there was no way for them to regulate or monitor those sales. It seems a little silly, but the reality of today's business world makes it a painfully understandable concern.
If the 990 is what we might reasonably assume it to be, I'd suggest anyone interested in a used 950 watch
Audiogon . That's where I've sold used equipment in the past, and it's worked well for me.