I was thinking about this stuff yesterday. If my physics education from 12 years ago serves me well, there are only three components to a wave: frequency, wavelength, and amplitude. A fourth component - distortion - is introduced by the analogue, which would be the speakers in this case (and every component that comes between the CD and the listener's ears). In our case, faithful reproduction of the original signal it what matters. But, how does an "audiophile"` know what is faithful and what is not?
It's my belief, from personal experience, that what a listener considers "great-sounding" speakers is not faithful reproduction (because how does one know if it's what the artist intended or not?) but rather the ability to handle increasing amplitude of the wave without "coloring" the wave with distortion (as perceived by the listener). There has to be an upper limit to this: for one, the listener can only tolerate so much volume without the eardrum itself distorting and for two, surely $25000 speakers don't have any property that would make them any less prone to distortion than say, $200 speakers.
This is why I think audiophiles are wasting their time and money. If you demand perfect reproduction, the only true source of the material would be to hear the music live, and *only* live. I guess you could also ask the artist how their work sounds on your system
My point to all this is that there has to be some kind of threshold of expense vs fidelity. I don't know where that is. The end result is so subjective that it's impossible to pinpoint.