One of my best friends owns a gun/outdoors shop in northern Wisconsin and he has an amazingly poor selection of knives - mostly Schrades and a lot of Chinese knock-offs. When I criticized him for the lack of quality he replied that he knows his market. Based upon his years of experience selling to the same people in a small town, he knows that a $100 knife will just gather dust -- no matter how much he pushes it. $20-$30 is the most his customers are going to pay for a knife, so he doesn't see the reason to take up display space with something that won't sell.
On the other hand, one of the best selections of knives I've ever found in a non-knife-specific store was in the heart of Manhattan during a trip to New York last year. I was killing time walking in and out of shops when I came across a big sporting goods store. I'm wandering around in there looking at everything from camping gear to basketball jerseys when I see a sign directing me upstairs for fishing equipment. There, at the top of the stairs, is a huge display case with probably 100 knives in it -- Spyderco, CRKT, Buck, Timberline, Puma, Busse -- most of the major brands and many smaller ones represented. The prices were a little higher than I would normally pay at home or over the net, but I was in NY -- everything's more expensive there. I didn't buy anything that day, but I sure looked a long time. It was true diamond in the rough.