This argument always bothers me because what it costs to live really isn't important.

At the end of the day Chinese worker A put in 40 hours of work and American worker B put in 40 hours of work.

They both invested 40 hours of their life into the project and neither of them are ever going to get that time back. Both of them will die at roughly the same age.

Just because someone lives in an area of the world where it's cheaper to live doesn't mean he should accept lower wages.