the quality of the build and materials. 600 for a knife is a little over the top but is far from outrageous spending compared to some stuff in the gun and knife world.
I gotcha. And I view those items in a similar way. But that's based on what I would personally be using them for. However- It's easier for me to see the justification when it comes to firearms than it is when talking about a....knife.
And this is only my personal opinion (which applies to ME)- I certainly don't mean to discourage others. If a guy has the means and wants to buy what he believes is a better tool- I'm all for it.