The "standard" for high end audio processing is Pro Tools HD/HDX, which does cost this much in its fully-fledged form. Users can run a CPU-only version of Pro

The "standard" for high end audio processing is Pro Tools HD/HDX, which does cost this much in its fully-fledged form. Users can run a CPU-only version of Pro Tools called HD Native which (along with its competitors like Logic, Sonar, etc) are useful and powerful programs. However they lack the power and depth of plugins available for the hardware-accelerated version of ProTools (and other hardware-accelerated plugins like UAD). I think the Holy Grail is and has always been to "go native" and get rid of these sorts of accelerator cards as money is better spent on the general-purpose devices that retain their utility better. But we still aren't there yet - when you load up even the best CPUs with lots of convolution processing, too much latency is introduced. So yes, I think there's at least a niche market for the $15K general-purpose computer that truly represents a "bottomless pit" of audio processing power. I haven't even touched on video editing or 3D rendering, both of which can be even more CPU intensive. When you add all these niches together, they still look like the original power-creative niche Apple was targeting 10 years ago with the Mac Pro and the Macbook Pro, and we still want more power.