I've had a few games listed as "for trade" on Board Game Geek (BGG) for a while and someone just offered to trade a copy of the HQ base game for my Heroscape "Rise of the Valkyrie" Master Set which I seldom play. I'm going to go ahead and take him up on it since I've wanted to obtain a second HQ game and I had it listed on my BGG "want list". As I mentioned here and on my blog article, BGG can be a good source for HQ stuff (here's a link to that article: http://yeoldeinn-heroquest.blogspot.com/2013/03/heroquest-shopping-tips.html). It's where I scored my copies of the Barbarian and Elf Quest Packs.
Heroscape is a good game (designed in part by HQ designer Stephen Baker) and I know that it still has a strong following, but I found the long set up time for the modular board kept it off the table for the most part. Great components though.