Guess I need to name-names for clarification.
Recently, a musical colleague called me to announce he had purchased a "Santa Cruz" era, Dumble modded 1960's Fender for around $15,000 and he was excited for me to come check it out. I really was surprised that, even with him playing through it, (a full-time session guitarist) I didn't hear anything dramatic in comparison to his twin reverb, except that the Dumble-modded variant was much more noisy.
I recently sat in with another music chum and played through his Muscle Shoals E53 and Mesa Lonestar 30 watt. He claimed to have paid about $3,000 for each amp and both were quieter than the $15,000 modded Dumble and sounded just as good to me, under a variety of settings..but, didn't do any more or sound any better than a nearly new Fender Blackface that we played ou
So, for the purposes of clarification, I would say that my opening statement refers to the boutique amps - in the $8,000 and up range. Some recent acquisitions by colleagues have gone as high as a claimed $30,000 for a single amp.
At the lower end of the spectrum, however, I can say that my owned-since-new Marshall JVM 410C doesn't blow me away either, despite it's lower $2,500.00 (current new) price tag.