I’d venture to say that someone that does this for a living on the high end easily has $20kmin stock parts that they know well to do this. Many good to better caps cost in excess of $300, and the quality of those is a total crap shoot when it comes to a final design.It doesn't need to be that complicated. Every designer has a "house sound" as I've heard it labeled. The actual electrical values often play an even more important part in the overall voicing of a speaker, than the quality.
Matching drivers that play well together (pardon the pun) is the very first step, before you even slice up the signal, to get a well resolving cohesive and dependable voicing.
Anti-phase measurements between crossover points (slopes obviously) where the drivers are at their best sounding are a good key way to get them to seamlessly blend across the frequency range. The argument that one driver alone that can do it all, that argument has merit.
Even DSP, requires knowledge of where to cross the drivers, if a fully active approach is to be undertaken. To me, it's the driver interaction, before the crossover is even implemented to shape the signal the drivers are fed, is the key to high end.
You can use relatively cheap components throughout, even the drivers to some extent, but if they won't play well together, if one simply won't vanish into the overall sound and reveals itself with colouration - your crossover cannot possibly win. DSP, fully active, with a crossover or not, driver matching matters.
Is this guy joking?