I saw those auctions, too, and was just as shocked. Like stressmaster5000 said, I think it was it's just the combo of two guys wanting the same thing, not really an indication of typical worth. Esp the 75 soldier. That one baffles me. That seller, though, does come up with a lot of nice hardware. Look though some of his completed listings - lots of old (30s and 40) soldiers. He sold a 30s Wenger soldier for about $35 a couple weeks ago.
eBay is funny though, esp with these knives. All it takes is two people who want the same thing and the price goes through the roof. Tonight I saw modern Craftsman with a "stock" picture - not even a pic of the actual knife - go for $32. I can buy a new one for $39.