Well there are a few collectors out there with deep pockets that the down economy does not seem to bother. I have been trading on eBay for a long time now and back when you could see their id's I started to keep a running list to keep track of who was buying and how much. With the changes in how eBay obscures your id's it makes it harder to keep track but I still can to a certain degree.
There are probably 3-5 deep pockets collectors that bid on these kind of rare knives. Of them only 1 is a member of a forum that makes his collection public. Another 1 is a very big buyer/reseller (Smartknives), but you will never see his bid until the last 5 seconds of the sale. The others basically keep to themselves. I have sold to one of them years ago when it was feasible to sell on Fee-Bay.
Also there are a couple of resellers that bid up some of the more rare pieces because they know their value and wish to resell for big profits. One of the high bidders on that list I know. The other 2 or 3 I am unsure of, but rest assured this bid price will go up at the end of the sale.