It's a market position, not necessarily just 'charge what you want'. You charge the highest premium that is still likely to result in a sale within a given amount of time. The higher the price, the longer it is likely to take to find a buyer willing to pay the higher price. As a buyer it matters when you see a person selling a new knife at 300$ and another selling it at 600$, you will likely buy the 300$ one. If thats the case, your not the demographic that the seller of the 600$ knife is looking for - the seller is:
-looking for someone who wants the specific features of the knife they are selling (thickness, finish, handle color)
-waiting for the 300$ knife to be purchased so that their knife will be the only one present on the market making the price 'take it or leave it'
-waiting for someone who sees the 600$ knife and does not notice the 300$ knife
Back in 2004 to 2005 there was a lull in the market when busse was revamping the line and introducing new models, it was during this time (2003-2004) that the fbm was first being intoduced. the only models on the market were SHBM's and BME's. I saw SHBM's go for 300$ during this time.
Now, take the seller who posts his SHBM for 1,200$, you might think "what the heck is that guys problem? thats 4x the cost of that guys SHBM in the same condition", and that would be valid from the perspective of a buyer, but not necessarily from the perspective of the seller. He isn't looking at you (someone who wants the lowest cost) as his sale demographic - he's looking for a buyer who wants his particular knife (which may be dead mint, or whatever) at his price. There are several things that can cause a market condition where such buyers are more likely: and it did happen.
Several SHBM's have sold for 1,200$. All that seller had to do was wait. So what seems like a ridiculous overpricing to you has ended up being a functional market process and tactic for the seller.