I wouldn’t go with a figure as my starting point. I do believe that some things need to be expensive. Putting a lot of hours and brains into designing a speaker and then making a limited series translates into expensive.
Brands are expensive. A brand speaker achieving similar results as no name will be considerably more expensive.
My notion of expensive is getting average quality for a pile of money. Small producers often suffer from this.
Specialized equipment is expensive. If you have a 3k DAC, that does nothing but turn digital into analogue, that’s expensive. Especially since by today’s standards it does nothing more than a 300$ one.
There’s a guy I keep seeing in small ads who is trying to sell a 1.5k stand for a TT. Waaaay too expensive.
But I believe speakers could go up to 15k and rightly so. I wouldn’t have the money to buy them, but I wouldn’t necessarily see them as expensive.
My speakers are 1.5k, but many, many reviewers saw them as cheap and some even said that for a considerable improvement in sound you would have to go beyond 2k. Seeing it that way, they are not expensive.
This is why I see it this way; if it was easy to do and if it didn’t ask for research, investment, know-how and craftsmanship, then all your Radio Shack stuff would sound as good as the big names, but it doesn’t.