Law of Diminishing Returns; where does it kick in?



I think that most of us who have been in this hobby for a while have experienced the "law of diminishing returns", the point at which spending a lot more money produces a little bit better sound or just tradeoffs.

I would like your opinions on where you believe this occurs in Speakers, Amps, CD players, and cabling.
ultrakaz
P.S. However you can put together a very good system that most people would find extraordinary for the price of a modest car.  
My system put to shame most of what i listen to for 500 bucks...

 The key is the mechanical, electrical and acoustical working dimensions embeddings controls NOT the price of the gear at all....

Consumerism is not audio.... Acoustic is.....