I go by "Xavier Blackthorn" on BGG...betcha didn't know I had a first name!
At BGG I was able to get a good deal on a big lot of HQ games and expansions. The end that result was that I obtained complete copies of the Barbarian and Elf Quest Packs for around $100 once I sold off the items that I didn't need. I discussed the HQ shopping opportunities on BGG in my sole blog contribution http://yeoldeinn-heroquest.blogspot.com/2013/03/heroquest-shopping-tips.html which I'll re-post here in case anyone is interested:
"This is a popular website for hobby board game players, and there are several forums, reviews and downloadable files dedicated to HeroQuest that are worth checking out. There are usually a few copies for sale on the marketplace located on the page for the game system and occasionally in the related forums which you can subscribe to. These sometimes sell for considerably less than current eBay prices and I've gotten some very good deals here on both game systems and expansions. Keep in mind that the expansions each have their own page, complete with separate forums and a marketplace. This website also facilitates game trading among members and as of this writing, there are over 400 copies of HeroQuest listed as “for trade”. Granted, many of these were listed years ago, but it doesn't cost anything to suggest a trade for something you already own. If you have some desirable board games in your collection, you can create a profile, list what you have for trade, search for members that have a copy of HeroQuest to trade who are also looking for something you have, and suggest a swap. It’s a little tricky to negotiate the website, but it could be worth the effort."