I think that the Law of Diminishing Returns really does exist, but the problem is perpetuated by the manufacturers themselves. I'm convinced that many manufacturers make a new component(as a prototype initially) then assign a value to it based on it's sonic standing amongst competitors products. So if a component is manufactured that has a potentially low retail price, and is astonishingly good for the money, then the public rarely gets the benefit of it, because the manufacturer jacks up the price so it sits nicely alongside competitors products in a similar price range. I believe this is rife in the cable manufacturing industry, where exorbitant prices are charged for cables with an apparant low material cost. Then when the pricing is questioned, we are given the usual "high cost of development' speil.
So basically, the standard could be a lot higher, for a lot less, and the point at which the laws of diminishing returns come into play could be at a much lower price level, if the manufacturers were brought to task over their peer driven pricing policies.
It's funny that this happens unabated in the high end audio industry, and the buying public rarely questions it.
I just bought a Toshiba unit that plays Video DVD's, CD's and various other discs. It has Dolby Pro and a built in 192khz 24 bit upsampler. It sounds remarkably good against my $5000 CD front end. I paid $59.00 for it, brand new from Best Buy. Now you tell me that the high end manufacturers are not 'price fixing'.
Rooze