I've found the domestic premium too be anywhere from 3X to 10X. It really depends on how much is being done. We sometimes build antennas, which are single layer

I've found the domestic premium too be anywhere from 3X to 10X. It really depends on how much is being done. We sometimes build antennas, which are single layer PCBs. The cost-delta at production volumes is about 3X. On a circuit board assembly I've paid 15x more to build in the US, where the turnaround time was significantly slower and production yield was worse. This is CM-specific, of course.