Kind of depends on where in China and what skills are required. When GE moved its high end appliance manufacturing back to America several years back, their overall labor costs were roughly the same between Guangzhow (IIRC) and Ohio or Kentucky. There are still lots of much lower paid manufacturing positions which cost a manufacturer a fraction of what an American costs, but here we're talking the cream of manufacturing, people running automated robotic and/or CNC equipment. This type of training takes years and require smarter-than-average people, and given the extremely competitive Chinese manufacturing market, accordingly command a large premium.
I don't know anything about the new Foxconn, but I assume that the low skilled manufacturing jobs will be mostly replaced with automation. Obviously this is much more difficult with repair than with manufacturing.