I own a pair of Sonus Faber Olympica Nova Vs. When I purchased them they were $18K. Since SF makes speakers of all prices, including ones many time the price of the ones I purchased, one can listen to the differences between their sub $10K speakers and their more expensive ones, and judge for yourself. I think there are audible differences, especially in the trebles and mids.
To me the argument about retail being too expensive is fatuous. I spent many years in retail and wholesale distribution. Everything you buy has multiple markups. It is my understanding that audio dealers get about a 30% margin on speakers, meaning for every dollar in retail they make about 30 cents. A normal markup for items in that price range. Also, on brand speakers like Sonus Faber, the distributor sets the price. That's why you don't see deals on new SF speakers or Magico or other good brands.
Before my Sonus Faber speakers, which are all hand made, including the drivers, I owned Golden Ear 2+, thinking I was getting a hell of a deal. To my ear, they sounded much better than their price. In the end, I had several pairs break. Withuot using explitives, whcih Audiogon frowns upon, they were cheaply made. And the minute I auditioned my Sonus Fabers, I realized what a good speaker sounded like.
When I have gone to shows, I have seen that the good stuff sounded better. If part of what you're paying for is R&D, the manufacturer also has to pay for it. Good audio engineers don't work for minimum wage.
Audio dealers are constantly going out of business. Do you think that was because they charged too much? I'm sure there are products out there that are too expensive, but for the most part I would say you get what you pay for. If you don't have $!8,000 for speakers (now $22,000 because of tarrifs), Sonus Faber has relatively inexpensive ones, as do many high-end manufacturers.

