Point of diminishing returns

we are all forgetting an important consideration, namely priority or valence.

what is the value placed upon listening to music, i.e., how important is it to really enjoy the music in comparison to other activities in life ?

if audio/music is very important improvements in sound will be more highly valued, than, as an example, an improvement in the experience of watching a dvd.

ultimately the point of diminishing returns depends upon the relative importance of an activity and the value placed upon the quality and quantity of an improvement.

Yea Barry. That is the most easy to understand explanation. I knew there was a simpler answer to a complex question. Just as the others, it's not definitive, but a great illustration just the same.

When there are more reasons NOT to buy than TO buy.

Meaning spending more money may yield improvements but there are downsides which outweigh the improvements.
For example, a bigger amp would have more power but sound quality would be worse due to extra gain stages or transistors/ tubes used to achieve the higher power ratings.

When you no longer enjoy listening to music because your system is way too revealing of recording flaws.