Dunno if this would work, but people could consider a scheme like 'house swaps' people do for holidays. Maybe collectors could loan out/swap a game for 6 months. I know freights costs etc could be a pain but at least you don't sell your game. Personally I can't see it working but who knows.
Interesting as I was toying with that idea recently and came up with this..
http://pinballswap.retrofun.com.au/I actually forgot about it until I read this thread.
I called it Australian Pinball Machine Swap because the Acronym for Pinball Machine Swap just didn't sound right. LOL
Maybe not a viable idea regarding interstate or long distance but in your local area.
The idea is to list any machines you would be prepared to swap out, and others nearby with machines can contact and arrange a meeting and talk about it.
If you think this might be worth a try the website is already setup, costs nothing to try it!
Cheers: Brettski... :)