In my area, of handmade valve amps, from the 70s, its starting to look like rising price of 70s amps is heading toward making it economic to start making amps by hand in the UK again, without having to rely on a reputation established 40 years ago, or making clones of Marshals and Fenders for blues lawyers. A new build valve head is heading to not being that much more than a rebuilt to good as new vintage one. I finally managed to sell a vintage head for about enough to have a new custom head built, so there is step one.
Thing is, I'm going to be buying most of the parts for the work I do from China, not just because its cheaper, but in part because making the parts isn't even allowed in Europe (valves) and thus far, my experience with dealing with far eastern suppliers has been far better than dealing with European ones. Maybe a bit deliberately ingratiating, but it beats the straight up rude and blaming me for their failures to deliver I get from suppliers I've tried here.
Interesting other note is the amount of fancy high end vintage bits, mostly the really nice valves people want for hifi, that I end up sending to the east.
True, the cost of vintages is starting to get a bit silly.
There have still been british manufacturers which have continued, but they've generally been smaller scale and still pretty expensive (Cornford is one that jumps to mind).
It is a valid concern regarding the production of certain things, like tubes. I'm sure there are ways to do it in a more environmentaly sound manner, thought that may not be a cost effective one