The result is exactly as you'd expect: the items sold by third party sellers on amazon have a large markup just to produce break-even margins. Source: my wife, who ran a business including third-party selling on Amazon for a while.
This is another hidden benefit of shopping on Amazon: they see my (egregiously long) shopping history. I'm sure they have some risk profile on me that suggests I'm not buying and returning a bunch of stuff to rip off sellers.
If I say something some pack of kids underwear is the wrong size, or a $15 LED light didn't arrive, or a pair of boots needs to get exchanged, it's dealt with in maybe 60 seconds of clicking on their site.
My guess is that people buying high-end headphones are just not comfortable with such setup.
I bought a product from a seller on their website once, but mistakenly ordered the wrong colour. Upon reaching out to them, I was told I had to ship it back myself (at a multiple of the item's cost), or buy a new one.
Meanwhile the product was listed on Amazon for the same price. Did I also mention that when I ordered the product initially, it came from an Amazon facility? Why does the seller get to benefit from Amazon's logistics but I get stiffed on the return?
I know how returns work with Amazon. If I buy directly, are they going to give me the run around if there's a problem?