Most of that $600 is BOM inputs where most of high end components worth $$$$$ is ultimately captured by US / western suppliers (i.e. chips, sensors, screens for iphones). The actual value of export from PRC in terms of material and labour is $, but still counted as $$$$$+$. Though iphone/high tech unique since US plays hand - sanction $$$$$ PRC components so Apple can't integrate them and raise PRC share of Apple BOM, which IIRC grew to ~20% and on way 40%+ (prc memory + screen) and now <20%. This is something PRC stats has started adjusting for.

No, that’s not how the math works. Apple Pay’s for the valued added, not the total value.

So if Foxconn is assembling a phone from components, they are paid for just that. The export is labor, not a fully valued finished phone.