Honestly I don't think they're so rare. They seem to be easily acquireable, for a price.
What really gets me angry is the ht terminators on ebay. They start out bidding at 99 cents and end up over 150! If those jerks who bid things up were careful they could be getting those terminators for under $30.
Yeah, but if they kept the price under $30, it would be easier for other people to win. And those buyers who are determined to win the item don't want that, so the bids are high to keep the competition away. There's no changing it.
Lemme put it this way. If someone really wants the item and was originally willing to pay hundreds of dollars, why keep it under $100? To do a favor to the other people that can't pony up? To give them a chance? Well, tough. If you want the thing and have the money, you'll do everything to make sure you end up with it. Not someone else. Otherwise, it destroys the entire point of eBay.