I just did a quick search of ended auctions to see what you were looking at, and I don't see that much variation in prices. Of the 20 knives shown, the high was $40 for a mint NIB King Ranch in the "sharper Idea" box. That would be pre-2001. Next highest was $27.78 for a mint NIB Senior Ranch in the last flag box. That would be post 2002. Five of these were listed at once by a seller on the 10th and he only got $19 each for them, to be expected when you "flood the market". Only a certain number of people are looking for any one pattern at a given time. Then $25 for a Schrade Walden in excellent condition. The Chinese copies seem to be going for $15-20. And excellent used non-Waldens for $12-20. New in the box knives bring more, the older they are, the higher they usually trade for. Excellent Waldens (pre 1973 1/2) even without the box command higher prices. Later ones in excellent used condition are excellent bargains right now. So I an not really seeing that great of a price fluctuation and, in fact, the last twenty sales quite well follow expected price structuring. Of course there is always the knife or two of any pattern that goes "under the radar" and sells for less than expected. This pattern was made beginning in 1970, so while there was only a few years of it being produced with the Walden tang, it was produced for more than thirty years under the Schrade tang, and is not rare.
Hope this helps.
Codger
