No offense meant by this Sig 230, but knives just don't hold the same interest as guns do for most of us-this is a handgun sight. Maybe I'm speaking for the many, when I shouldn't be(I'm sure someone will let me know).
Here's my theory. When I was too young to buy my own guns, knives were fascinating things. I spent a lot of money on them. As I got older, knives were just another tool. I see my students with the same pattern of interest. They always want to discuss knives(even fantasy swords) with me, because they can own them, order them, buy them, ect. As soon as these same kids hit 18, all of the sudden their questions about knives turn into guns. Don't get me wrong, I still love a good knife, and during hunting season, there seem to be more questions on this sight(ar15.com) about knives/multi-tools.
Oh, BTW, I still collect bayonets for all of my old Military rifles, but they are just an interesting accessory. Heck, some of them are worth more than the gun! Putting a 1907 sword-bayonet on a P17 Enfield just makes a nice conversation piece!