What is your experience with the law of diminishing returns ?

No experience so far. $10k power cord replacing $1k power cord with $5k preamp or power amp, anyone ?

inna"I have not encountered it yet."
That is because the components comprising your Music Reproduction System must progress beyond budget, entry level, mass produced equipment you have not yet entered the circle, realm, and world of true high performance, high end, tight specification audio.

Clearthink may be onto something.  Depends on where you snap the chalkline for diminishing returns.  And granted my 'why did I do this' with a $500 upgrade may be chewing gum money to someone else.  Then again, I realize that I come from a time when this hobby wasn't about seeing how high the price tag could go.  

Rich 

30 years ago, I walked into a high end emporium and heard audio "holography", just recently I acquired it. This is the point of diminishing returns; it's impossible to put a dollar figure on getting where I am, that's because money and knowledge are interchangeable; I put a lot of time and study into this endeavor. Many will never get here, many more, like the fox and the grapes, will say "That's not where I want to be".

Once an audiophile gets here, the question is, how do I make it "Mo better"? And the answer is, "I need a pound of money".

No experience my returns are all great.