Samsung doesn't have to move plants to China to benefit from the lower wages, they can simply contract Foxconn to assemble the devices. And they do, according to this NYT article: http://www.nytimes.com/2012/01/26/business/ieconomy-apples-i...

The ExtremeTech article makes a lot of calculations based on the assumption that Samsung assembles the Galaxy S3 itself, but they don't provide any evidence of that.