The Bloodstone modules are a special situation right now. There's a lunatic game dealer in the U.K. who insists the out-of-print RPG market is "undervalued", and he's trying to prove it by "cornering the market" on H1 (and possibly the rest of the H series, but H1 is his special fixation). He's spent most of the past year bidding those things up higher than they're worth, than turning around and trying to resell them at even crazier prices. The few sales he makes are mostly to ebay newbies who don't know they're being ripped off.
This guy is widely despised over at the Acaeum. If you want to see how much, search their forums for the word "cougar".