They would only be 4th on this list
Can you imagine dropping 10 grand on a pair of IEMs?
www.headphonesty.com
much of it is to do with complexity
The ones I listed have 11 drivers per ear
One Dynamic driver - probably for bass
Two types of planar driver - probably for treble
8 Balanced Armatures - fill in the areas not covered by other two, mostly mids and treble I expect.
Fitting all that into a small space, and making it sound good, comes with the ability to charge prices people will pay.
Maybe not me. But others.
There are headphones that cost more again but apart from ones covered in gemstones, the most expensive you can buy now is
but the cost of those includes the amp that is required to run them. Approx 60k or more.
Those are electrostatic headphones compared to the normal headphones people are used to. They need special amps - energizers - just to run them. Video explains differences between normal, planar & electrostatic:
most of the expensive IEM seem to have electrostatics now. They are also becoming available in much cheaper ones (compared to the ones on list anyway).
Next IEM I want has 9 drivers in it, but its no where near their prices.