Also, It does not mean 16nm is cheaper than 20nm... the smaller the feature size, the more the wafer costs. Also, this is aggregate revenue at the foundry, and is ignoring things like tapeout costs.
Not trying to crap on the tech, but it's not so simple as we can merely go to the fab and get small quantities of full custom, 100% yielding chips, for 6k ea.
That doesn't make any sense because errors are an inherent part of the manufacturing process. If errors in the manufacturing process make 1% of the area unavailable that means perfect yields could at most be 99%.
I would be VERY shocked to see 100% yield... theres only so much you can do on chip though this strongly depends on what your definition of a working chip is :-P
That probably means their wafer yield is 100%.
As for wafer prices: https://anysilicon.com/major-pure-play-foundries-revenue-per...
It's $6k for all wafer smaller than 20nm, which means 16nm is somewhat cheaper than that.