A HUO spiderman sold on the gold coast recently for $4600. It was in excellent condition.
Another SM sold for $5000 to a collector who really wanted it from interstate. I was asked to go look at one for 2 different buyers.
Prices of 2nd hand sterns have come down since new Sterns can be had for $5950 with 6 months warranty.

Also, since a QLD seller recently sold a whack of brand new in box Stern Ironmans (plus other titles brand new) that he bought in from Hungary, and sold them for $4750 or less, that has also brought the prices down in the local market. I was offered one of these Hungary delivered Ironmans recently for 4 grand. It only had a few hundred games on it.
It would be hard to sell a 2nd hand Ironman for more money than people paid for a brand new one since everyone up here knows what people recently paid. Having said that, the Hungary delivered machines also have no factory warranty, which also brings the price of those ones right down.

Any 2nd hand stern in good condition is worth considering. An australian delivered machine will hold its value better. The Tron looks like good buying.

$4600 for sm is a bargain...good unders on one of the best if not the best stern pin made.
There were 4 nib IM from that stock and one used, hardly a whole whack, the rest were nib Avatar( 3). Warranty means little to me when you have beaky the super tech and other quality techs in brisbane to help with any problems, if there are any.It sure beats paying to send it back to sydney and waiting..waiting waiting, after paying top dollar for something that should work with no issues.
Should have grabbed the IM while you had the chance, 4k was a great deal for a game of that quality..good luck getting one at that price again.
It shouldn't matter if you got a great deal and others know the price..bad luck to those who didn't strike while the iron was hot...lol..if you picked a baragin for $1500 and it was worth $2000 or more to a prospective buyer would you sell it for $1500...of course you wouldn't.