[bsder]

Is there no local PCB manufacturer near you? Normally, local manufacturers can do that sort of thing for about $2K or so with quick turnaround (<1 week). Assembly is normally anywhere from 1K to 5K extra depending upon complexity.

You should be able to buy quite a few local turns for the price it would cost for you to spend time in Shenzhen.

Unless you're Chinese is very good or you have a trusted local contact, you're not likely to benefit much from heading to Shenzhen in person.