The primary value of a good amp is not frequency response. The primary value is if you have music with great dynamic range, a quality amplifier will be able to manage the power requirements, which can be pretty extreme (especially into difficult loads where lesser amps will be under measurable duress). Recording quality has changed in that most mass market recordings are auto tuned and compressed so they sound loud... the problem is they have no dynamic range. In addition, some amps can essentially be a tone control if people want a particular sound (e.g. class A or tube amps).What do you mean by "low quality power" besides being marketing speak for cable and power conditioning companies. The reason high end audio sells is for on reason only-expectation bias! It's more expensive so it must sound better. Besides, so called high end audio is lost on us over 25 who may not hear above 14k.
For me, high end audio sells because you are getting craftsmanship and great design. I have gear over 50 years old that still performs great and would not even contemplate selling. Most electronics sold these days are disposable... they are unrepairable and quite simply, who would care to own it 20 years from now. If you buy the right high end gear, and can use it for its basic functional purpose, you have equipment that long term will be very inexpensive and give you a lot of happiness.





