I wouldn't listen to what the dealer suggested as a price; after all, it's in his best interest to make you want a NEW safe.

It might work better for you to offer it for sale on a site such as this one, if you're looking to make money with it. People ask for the silliest things when buying a house, so it could be used as a tool for negotiation, but I actually think you'd recoup money and have it go to a good home by advertising it on firearms forums.