At the end of the day, its always going to be hard parting with a piece of history to an idiot who puts it back on ebay.
I have only had one business dealing with one video machine operator over my star trek voyager video game, and the seller was a moron.
But unfortunately, there are limited people who love the items first, and the money second. Thats what seperates the true collector to a marketeer.
I would only sell my machines if i was ever selling to a collector/user who i know would appreciate it. Seeing something you have put some blood sweat n tears into, being carried off by anyone but a collector would be heart breaking. Long live the true collectors i say.