The point of diminishing returns is just past the amount of money you have spent and justified to yourself as necessary to achieve the sound you want, and just before the amount of money other idiots have spent on their systems for sound refinements that are clearly not worth the money.
It is also right at the point in the price performance curve where component comparisons shift from differences described as KICKS ASS to differences described as "I think I can hear...."
It is also right at the point in the price performance curve where component comparisons shift from differences described as KICKS ASS to differences described as "I think I can hear...."