I am willing to spend time and train my ears. Let's start.
Can you please define high end for me? Does that mean expensive gear, exotic cables? Or rather what does high end means? What equipment? How about setup? Should the room be treated/non-treated? How much treatment? I want to do it right, because so far, I don't hear the difference between cables, leave alone burn-in in the cable. Can you please guide me?
As for listening to different setups, yes, I have listened to some ranging few hundred dollar/speaker to 5 digit per speaker. But I have hard time understanding what "high end" system means. Have to find out what it sounds like.
I appreciate the interest and I'll fill in what I can from my experience.
First, for training your ears careful listening to live unamplified instruments and voice whenever you can is the greatest help. There is a lot of detail that we can hear but without attention is taken for granted and unnoticed. As an example, listening live to a cymbal being hit by a drumstick, with attention, you can hear all kinds of detailed resonances as the metal is struck. Most people are unconscious of the level of detail that could be perceived through hearing because, I feel, we are so visually orientated. But with attention to what we are hearing we can develop our ability to hear details and discern nuance. It is no different, I believe, than practicing 3 point shots in basketball and finding that with practice you improve, as one example of lots of things that you can get better at with practice and attention.
The realm of audiophiledom I follow revels to hear this live level of detail for all instruments and voice when reproduced by their audio system because this detail brings out more of the sounds of the instruments and the artistry of the musicians and brings on that live magic of the music.
A high-end music systems goal is to faithfully reproduce the music that was recoded. One evaluates a high-end system by listening and using your experience of hearing live instruments and voice against how well the audio system is reproducing that live detail of individual voices and instruments.
If you are familiar with symphonies, one area you would listen for is when the violins are playing does the audio system reproduction make them sound like congealed mass or can you get a sense of individual violins playing as you would hear when you are at a symphony. That separation from congealed mass from a low end audio system moves towards high-end systems as the system gets better at giving you that perception of separate violins, or the airiness of the oboes playing in the back, or the sense of individual voices singing in the chorus. As the reproduction quality of the high-end audio system improves, you can get a sense of the hall the orchestra is playing in, etc. This is the hobby.
No high-end system is perfect. Entry level high-end systems are not costly.
There are many sonic wonders at low prices and cost does not always mean better. There are plenty of "audiophiles" who are chasing the next costly piece of equipment even though its reproduction of instruments/music, when compared to live unamplified sound, is not a step forward.
As a note, A few weeks back I helped a friend setup an entry level high-end audio system. On my recommendation he purchased Pioneer SP-BS22-LR pair of speakers (designed by a high-end speaker designer and at a price that is remarkable for performance) along with a Cambridge Audio entry level integrated amp and using a dacmagic dac. Good entry level system at a very affordable price. He had it hooked up with lampcord for speaker wire and the first time I came over to hear it I brought along my spare Kimber Kable 8tc speaker wires. After listening for a bit to his system we replaced his lampcord speaker cable with my Kimbers. The change in sound knocked him off his chair. A step in the direction of hearing further separation and wholeness to instruments and voice, better sense of air around instruments, etc.
So a brief summary, as I know it, of training your ears and what true high-end equipment is.