If Sematech is serious they better bring the wafer mfgs. into the mix. One maker producing some poly wafers isn't going to cut it. Intel and Samsung will probably fix a target price of 1.5 to 2 times 300 mm for the 450s ignoring the fact that they will have more than 3 times the silicon in them including kerf and grinding loses but, not crystal pulling. If they demand first through (no remelt) crystal the costs will be staggering. I hope PV can absorb the reallocated material!
The litho problems will be harrowing as the line widths are approaching physical limits of resolution while the local and global flatness demands on the wafer and equip makers are just as difficult to achieve. This will be the hardest migration yet.