Why do mic tube preamps cost so much more than tube guitar amps?

So I'm touring the PRS Guitar factory, and go into the amp r&d area. After talking to a couple of engineers and going over the guts of their tube amps, I realize that these guitar amps are at least twice as complex as microphone tube pre amps. On top of that, the PRS amps made offshore are very, very cool and substantially less.

It seems to me that we've been paying a 'mic preamp' premium for a very long time. Is there any relief in sight?