Up till about 5 years ago it was cheaper and faster to get a turn out of Asia than the US. I have no idea now. This was true for anything more than 1-2 panels (24"x18") with 4layer 4mil trace/space and no blind/buried vias. You could easily get 4 day turn (2 day hot lot was double).
We really wanted to use local or US manufacture, but it had multiple problems:
1 US worked 9-5 so you had to deliver by 9 whereas China you could deliver at 5pm.
2 US didn't run equipment on weekends, and often better equipment only 1 time a week.
3 In US the equipment wasn't constantly running so calibrations went off and sometimes multiple runs were required to dial it in.
You could order a couple of panels form Asia on Friday at 5pm and have boards available by courier Monday before noon for <$4k. All of that assumed that there were no problems or questions on the gerbers so you needed to do a really good review and know their capabilities. There were places in Vietnam, Thailand, and Shenzhen that did the work. We stuffed (SMT) the PCBs locally, but that was moving to Asia as well since availability of some parts was easier there. I'd worry about counterfeits more now.
That was mostly a concern with the CMs. We had the advantage of owning the Main ASIC FW and the Driver so a serial# challenge response could detect fakes. Difficulty was doing that without implementing public key on a tiny micro and keeping reverse engineering difficult.
We really wanted to use local or US manufacture, but it had multiple problems:
You could order a couple of panels form Asia on Friday at 5pm and have boards available by courier Monday before noon for <$4k. All of that assumed that there were no problems or questions on the gerbers so you needed to do a really good review and know their capabilities. There were places in Vietnam, Thailand, and Shenzhen that did the work. We stuffed (SMT) the PCBs locally, but that was moving to Asia as well since availability of some parts was easier there. I'd worry about counterfeits more now.