Well there are several points to look at it. First of all I think Ebay, if one is careful can be a good tool in several ways.
Of course since I am a neophyte I would never buy an expensive knife off of there for with out running by the experts here first, and what I consider an expensive knife is only about 50.00!
I have learned a lot just reading the post about knives on ebay on this forum.
Secondly, I have gotten some real bargains off of there, I decide what I will pay for a certain pattern then I bid on them until I get a deal. I don't go past my pre-set limit, often due to the wife's medical expenses I can't. That means I miss a LOT more than I get, but most often in the end after several attempts I will come away with the knife I want at a price I can afford.
My third point is that if in fact ebay has driven up the price of collectible knives, it just makes my collection, as modest as it is, worth more. If there was never an increase in the price of knives that could never happen. I am glad the price of the Reproduction Remington Bullets has kind of taken off a bit. I like the price of the Camillus Yelo Jackets has climbed some. I got some while they were cheaper and they have increased nicely.
And finally, I am not so sure that ebay is to blame for all the price increases. In fact I wonder if it has actually kept prices down a bit.
For example, I do some saddle repair and make leather goods for civil war re-enactors on occasion. I sell them on Ebay instead of going to re-enactments and it saves me set up fees, registration fees and above all GAS! It lets me sell a high quality product at near the same level as mass produced goods that some import from Pakistan.I expect knife dealers feel the same way.
There is no doubt ebay and other sites, like this one, open the door for new collectors, but is that a
BAD thing? It does increase the competition for old knives, but what you may consider high prices now will seem cheap in a few years as the hobby grows. I expect no matter what the time period the guy buying the high end Case thought it was expensive.
Just my opinion and worth exactly what you paid for it...
For a 1972; what happened to the "good old days"? When you could go to a show; with a fist full of $100s, peel off 15 or 20 and walk away with a roll of Case stag, greenbone, or real red bone. You could hardly give away; a knife, newer than a 10dot.
I see from the bidding history that he had 3 more bids after the winning bid, I wonder how much he really was willing to spend. Nice knife, for sure. 
