I've recently been bidding at a Dutch eBay-like site for a set of games, including:
HeroQuest Advanced edition
HeroQuest Return of the With Lord
HeroQuest Kellar's Keep
HeroQuest Mages of Morcar
(all in Dutch)
I just bought a normal HQ set, with some extra miniatures too (some undead and greenskins, so RotWL and KK can be played with what I have). But I was looking to get the AHQ set, with the three addon sets. The owner mailed me that he had a bid of € 80,- and wanted to go with that, unless I had a better offer. My last bod was € 75,-... I figured I could always sell the BM, DW and Atmosfear games to get some money back, but now that I have a normal HQ set, I'm in doubt if it's worth it... All the addons can be downloaded, and printed. The only thing missing would be the figurines.
Should I go for it?
Would the other 3 games make me some money if I sell those?
To be honest, the figures are the easy part to replace. There are thousands of miniatures you can use instead. Mantic comes to mind, a really good place to start with for Undeads, they have some awesome sets.
I see Heroquest more of a genre now, as in going dungeonbashing with friends. Id rather spend some money getting lots to use, instead of spending a huge pile of coins just to get the original parts.
*Edit* I might be rambling a bit now, unrelated to what you wrote - but anyway :p