Quality
I can't remember where it was, but I recently read an opinion by someone familiar with knives, knife materials, and knife applications, to the effect that, for a knife of this general class, quality doesn't really start until you get above $50, and more often above $100.
I've handled a few of this type, and I'm generally inclined to agree.
It's not that I personally feel that a quality piece of this kind ought to cost $100 or more, but it seems that something about either the workmanship required for that quality point or the demand from fans of the type that pushes it up into that range.
Consequently, if I were shopping for something of that size and shape and general form, I would probably feel "there's a catch" if the price didn't at least reach $75 or so.
I'm not the guy to ask, though.
CDR_Glock or hso, on the other hand, could probably give you a detailed rundown on what goes into a quality piece.