"The Ultra High-End Speaker."

I have always liked the science behind Lansche Audio.

https://www.lansche-audio.com/en/ 

Although the site is under construction one is still able to get a sense of what they are about.

What I like is the attempt to capture the entire range of the frequency response as it pertains to the human environment. As many have mentioned room treatments would also have a tremendous affect.

A good friend had a pair of the Revel Salon 2. A really solid performing speaker. He traded them in and got a pair of Rockports which he regretted. He then invested in a pair of Lanche 8.2 and never looked back. IMHO - the differenes were, that the Revel Salons had alot of energy and really good imaging. The Rockports, looked cool, but fell short especially given the price tag. And the Lansche's - the best way I can think of to describe it is that extremely clean (not clinical)  detailed music enveloped the entire environment. 

I have used Lansche's approach as a guide in my own system as I cannot afford $200K++ for the 8/9.2 models.

Inspired by thier design - the active woofer seperated from the passive midrange, which in turn is seprated from the plasma tweeter(also active) - I added a pair of subs to my speakers, and then also added a pair of "Super Ribbon Tweeters".  Its far from matching the 9.2 Frequency response, 18 Hz - 150KHz however it has signifigantly expanded upon what I originally had for a fraction of the price.

My next investment will be in room treatments.

Happiness is what we all seek. If you take a poll of 100 people, you will find several opinions. Sometimes we have to align contentment to our bank account. When I moved to the USA from India, I had a pair of JBL speakers that cost me $100.00 a pair. Immense satisfaction they gave all my friends too. I have had fun experimenting with Wilson Audio, Martin Logan, Meridian, Vandersteen, T+A, Vivid Audio, etc. All these speakers were wonderful as I took time and focused on every detail, Audio Stands, Cables, setting up speakers, and optimizing my ECO system. I learned that getting power right was the biggest and cheapest improvement. Setups change but the love of music stays. I was the first store to bring in the Wadax reference DAC and Streamer. It was stunning. What you hear in that CH 10 series system is like no other. Mind you, I have a CH Precision MONO DAC at home and it's just fantastic. I just know that the Wadax system is amazing. That's OK. I own that too. I have customers who have a Technics Integrated with a pair of Stenheim Bookshelf speakers. They play live music with several amazing conductors. They are just content with their system. Pay attention to details. You sit in your home, that's your castle, your ECO system. Enjoy. Each and everyone matters as we all love music. 

OP   what price point does the ultra high-end start?

The price doesn't matter in hi-end audio. The performance matters. The ultra high-end audio must sound closer to the original music. 

The only ultra high-end audio in the world is the Wavetouch audio/speaker since WT is an only natural sound system. All others are just hi-fi or low-fi. Alex/Wavetouch

Pink Floyd – Time. Wavetouch V2 spkr, Live recording

I agree with Paul McGowan, PS Audio. 

The definition of High End Audio

Its what your ears and wallet like.  A $1k systen can bring you musical bliss like $100k system. My Yamaha MX1000 with B&W 803N only cost $3k and sounds wonderful.  Price will always be subjective in this hobby.