What is the cost of a mask when the capacity of the existing factories is tapped out and (in principle) one more mask requires a new factory? It's fuzzy when th

What is the cost of a mask when the capacity of the existing factories is tapped out and (in principle) one more mask requires a new factory? It's fuzzy when that point comes exactly, but it kind of has to exist. If you want to say the cost of masks is exactly what current operations require, then that one mask must be millions and millions of dollars. So who pays for it?