If you thought iPhones are expensive now how much do you think they will be built with American labor? How many Americans do you think will want those jobs building iPhones almost nonstop for up to 12 hours a day?
At any rate, I think at some point we need to stop looking at the economic argument and do what's best for US labor, US citizens, and human rights/health/the environment worldwide. Just how much are cheap electronics worth?