Save your breath. We're beyond reason in personal audio now. Shure just released a $3k flagship iem. JH's flagship is around the same price. The AK380 costs $3.5k. We can only wait for the bubble to burst.
The bubble will not burst. There will be ever-more expensive head-phile gear released. But these releases don't DRIVE the prices. Companies build and offer expensive products because they believe there will be buyers at the (specs+features+SQ)/cost=value point they intend to occupy. Sometimes they are right in their assumptions, and sometimes they discover they mis-judged the market, oh whoops.
I am willing to accept, more or less on faith, that this new Sennheiser is in fact better than any other headphone ever previously made. Selling it at 55,000 Euros is a double-edged sword ... at that price, it NEEDS to clearly sound better to 90%+ of people than the competition, or Sennheiser ends up with serious pie-face to their reputation. They would not have released it, unless they were very very sure it met that test. (IMO).
But as consumers, we each make individual decisions to buy, or not buy, gear according to our own calculations of cost vs estimated value & enjoyment. I will never own an Orpheus. I'm totally over that already. I can set it up in the private jet I don't have, parked on the private island I don't have, and daydream about it occasionally while listening to great music on my affordable-for-me gear that I do have.
It took 25 years for Sennheiser to top their previous best effort. And they've created a product so expensive that few audiophiles and/or music-lovers will ever own it or enjoy it. And they probably won't affect sales of the Stax SR-009 and related gear at all ... anybody who can afford the new Orpheus without a deep soul check won't need to make an either/or decision.
Meanwhile, in the past year or so, Schiit Audio has released two great amps, the Ragnorak at $1699 USD, the Mjolnir 2 at $849, and three great multibit DACs, the Yggdrasil at $2,299, the Gumby at $1,349 and Bifrost Multibit at $649, plus several novel USB-cleanup products. All of these products are incredibly disruptive, sometimes because of new technology, but always because their specs and SQ exceed those of most of the competition that is 2, 3, or 4-times as expensive. (Or much much more, in the case of Yggy.) And they're shipping thousands of them every year. In other words, we're buying thousands of them, and improving our sound systems.
And Schiit is by no means the only company innovating and redefining the value frontier from the bottom up. We have at least three DAPs and one cellphone about to hit the market, all under $1000, that appear to be poised to give Astell&Kern some serious heartburn. (The Questyle QP1R, the Onkyo DP-X1, the Fiio X7, and the LG-V10 that I know of, there probably are more.)
At this year's RMAF/Canjam, Andrew Jones' new ELAC speakers, mostly under $500 as I understand it, were in the "HIGH-fi" suites along with the $20,000 to $100,000 speakers systems, and reportedly very few people who heard them thought they were out of place.
Let the good times roll.
(I will shut up now. For at least 6 hours.)
Edit: In fairness, I must mention that I consider the Senn HD-650 to be one of the greatest values in all of audio, and it's been in that position for more than 10 years.