I recently priced out getting a PCB done in China and its insanely cheap. My design isnt complicated, a few ICs, a few connectors, an a dozen or so passives. PCB manufacturing, parts, and soldering/assembly is on the order of $10-20 total per board and that is with zero volume discounts. The parts alone would cost that much in the US, and I suspect the sort of companies that you contract out to also aren't really interested in tiny orders so they would probably quote huge setup fees (looks like your average order so far is ~$7000).