The cost of labor per iphone is about $20.00/iPhome. So made in the USA: let’s double that to $40.00/iPhone. Each iPhone costs around $800.00. A $20.00 increase is around 3%. No big deal.
You have to figure in the US they are dealing with HUGE regulations, OSHA, matching payroll taxes, workers comp according to payroll employee benefits, I am thinking about $100.00 cost per phone STILL worth every penny!!