Actual cost for made in the USA, at this point, would likely be higher than that, because of the law of supply and demand - price going up because demand would outstrip what a US factory could supply. Apple couldn't produce them here in the same quantities, because China can provide several hundred thousand skilled workers (skilled enough to do this work - yes, it's not rocket science, but it does take some skill) who can all work in a concentrated area in a complex of factories. It would take a surprisingly long time to spin that up in the US. Yes, you can find a lot of people who might say they're willing to take those factory jobs, but you find them spread all over the country. For it to match what China has to offer, you need to uproot all those potential workers and concentrate them in one area - a county or two in one state - and then build the enormous factories there. (And it's not just building the equivalent of Foxconn, but also all the smaller factories that manufacture subassemblies that feed into Foxconn - components of displays and batteries and lenses and camera sensors and circuit boards and connectors and gaskets and so on.)
I'm not thrilled with having everything manufactured in China. I'd like to see a lot more manufacturing done here (be able to trade with other countries because we want to, not because we have to). But getting the jobs back here takes a lot more than just wanting them and having X number of people wanting to do those jobs.
I suspect it's entirely possible that Apple will eventually move a bunch of manufacturing here, but in the form of very highly automated factories. Robots doing the work, people monitoring the robots. Likely in a wave of setting up smaller automated factories in many countries around the globe - would cut down on shipping and tariff hassles, and make them more resilient when faced with problems in one area (like they're currently seeing in China). Once they come up with working designs for highly automated factories, they can replicate (no, not Star Trek style) those factories around the globe.