Been thinking about this and i reckon you are better off selling what you can privately and then having your own private auction on the Gold Coast somewhere.
Your problem is trying to shift a shitload of machines at item price.. after all its a fat wad of $$$ that you want, not dribs and drabs coming in as you know damn well that a vast amount of this money will be frittered away.
Only way to sell in bulk and get good coin is an auction arena... you have MORE than enough machines to do this and Gold Coast is easily accessible to Sunshine Coast, Brisbane, NSW etc