I'm no watchmaker, of course, but I can't see that they are much more fiddly than any other part of a watch. I'm sure they must be though, in some way that isn't obvious to me. And there will, no doubt, be a hefty mark-up 'just because'. At the end of the day they look quite neat, but they just (by design) go round in circles once a minute, so I can't get massively excited by them.
Now the JLC gyrotourbillon on the other hand - say in the Reverso - that's something I could see me selling my mother for. Any takers?