Also, I'm not clear on the arguments presented in the slides. The transistor normalized price curves for 20nm and 14nm do eventually cross over the preceding curves, unlike the 40nm curve. And even putting the same transistor count on a smaller process node can result in lower power consumption once the leakage problems are mitigated, so the value is increased.
Edit: For historical background, here's a fascinating conversation from 5 years ago between Morris Chang (founder and chairman, TSMC) and Jen-Hsun Huang (CEO, Nvidia):