That's what happens in the secondary market; The DMDC was released at the bargain price of $79.95 (plus shipping, of course). Your best options are:

1) Be patient: Old Scrap Yard knives are occasionally sold for much better prices than that. Also, watch places like the BladeForums Exchange instead of eBay -- not that a bargain doesn't occasionally make it through on eBay, but you'll be competing with a huge customer base there, many of whom have more dollars than sense. Learn about what you want and decide how much you're willing to pay, watch for the deal you want, and jump on it if you find it (bargains can sell within a couple minutes on the Exchange).

2) Bussekin (Scrap Yard, Swamp Rat, and Busse Combat) knives almost never decrease in value -- you'll get the best price by ordering when they're sold by the company. I've bought Sus Scrofas for a little less than retail, but they're an aberration (and I expect those prices will climb too once they're no longer available from the Busse Company Store) -- secondary market prices are usually at least $50 more than the release prices, often $100+ over retail for rare or very popular knives. After the Blade show, there'll often be a ganza posted on the Busse Combat subforum on BladeForums; occasionally, leftover Scrap Yard knives have even been offered ("dog bowl" sales) on this forum.