Once you get to a certain point in classical guitars every instrument sounds different.
I think I paid $2K for mine, I’ve played guitars int the $10K range, but my ability really doesn’t justify them. It would certainly be interesting to hear the difference in person with a $275K guitar.
The way most of these bespoke guitars are sold is that specialist shops have standing orders with the luthiers with in some cases lead times in the years. They then mark them up accordingly.
I have a couple of low production run electric guitars, that guitar shops basically source the same way, though the prices don’t really explode in quite the same way.