Before collecting props, I was more into affordable replicas... and I didn't quite now that props could be found either.
As opposed to Star Trek where you can get some phasers to replaces the MR replicas... well at least if not from TOS, it's unthinkable for me to ever be able to get a lightsaber prop so I'm satisfied with those.
Darth Vader - ANH - Dual Signature (Bottom right)
Got this one a few years ago when you could still find them on Ebay. Never saw an Artist Proof version of it for sale.
Luke Skywalker - ESB - Signature - AP (Bottom left)
Luke Skywalker - ROTJ - Signature - AP (Top)
Ebay on my sense is all about luck. Sometimes you have a few buyers rushing for the same item, sometimes seems like no-one wants it.
For the 2 Mark Hamill signed one, it was those moments I was the only buyer and for anyone buying items on Ebay they will understand directly how fortunate it was for me.