When someone tells you it's a $40,000 amp, does it sound better?

One important aspect to recognize is that when you compare amps from different companies you are comparing different house sounds. Given we all have different values, we will prefer different house sounds more than the particular implementation.

So, say I like Audio Research’s amp sound more that Boulder. A $20K ARC amp will sound better than a $40K Boulder. But if I liked the Boulder sound my choice might be exactly the opposite.

Within house sounds (companies) the sound quality improves with greater price (let’s assume high end stuff > $5K), I don’t think I have ever heard a violation to this generality.

So, I think when you think about your experiences, you need to incorporate this into your analysis. Assuming you are not just biased against high cost. This will either leave you with too little data to draw a conclusion or likely that price / performance has a direct relationship. The slope of the line formed with these two variables will depend on how much you value improved sonic quality.

No. The idea of diminishing returns of quality for investment happens much sooner than $40,000.

Howiver a $40k amp does have the potential to sound bigger and more dynamic in a much larger space than a much less expensive amplifier especially if that price is for mono block amplifiers,

It would also presumably have the capability to power much larger more demanding speakers.

I have heard $40k VAC amps sound remarkable and $40 VTL

amps sound awful.

I’m just grateful the $20K VS $40K is not a real world consideration for me and that I’m happy with what I have.  It suits a far from ideal room that probably can’t be properly treated short of removing or covering a 30 foot wall of large windows.  How much better is Eno’s Apollo with a tranquil view?  Even at that, if I contemplate the maybe $7,500 in my analog system, it seems a bit crazy.  At least that used to be a good used car with lots of legs left.  My normal friends with their Sonos or UE Boom Bluetooth speakers and Spotify on the phone would plan an intervention.  Luckily I don’t have audiophile friends to egg me on.

yes

I totally think expectation bias and looks has a huge play. I also believe a 40k amp sounds better than a 5k amp on average. When get into the 20k plus range it’s probably more about looks than sound quality.

low volume for smallish room I think you can get amazing sound quality for a fraction of the cost. Don’t think most people could tell a difference.