Some people take the time and make the effort to raise their own meat, Vegetables, Fruits, nuts, berries and such, others Hunt, forage and Gather.
Still others find it a better use of their time and $$ to just go to the Store and buy such things.
Spending extra to get the knife aftermarket allows those who want a product to trade effort and time for $$ and still get what they Desire.
I do not like the long wait for a Factory order, I do not often find just the right knife at the Company Store every time I want one.
On the other hand if I make it known that I want a particular knife, then there are a few people that will get one hoping to trade it towards some other knife I already have that they want.