That probably varies, but my understanding is that makers generally have prices set for when they sell direct to customers, and "wholesale" prices they provide to a retailer / dealer in exchange for the buyer doing so in bulk. The level of markup between the wholesale cost and final price from a given dealer can be agreed upon before a bulk sale is made, and I assume that with some minor adjustments or specific purchasing deals, most dealers / retailers see about the same wholesale cost.
For the reason why the retail prices would be so high, I think that comes down to supply and demand. If you can afford to price your knives highly because you know they'll sell at that price... I'm pretty confident that in most cases, the final retail price is agreed to by both the maker and the retailer before anything exchanges hands.