I understand raising prices because of increased materials cost. But unless Portra uses significantly more silver than Ektar, or higher priced dyes or something, that doesn't hold. And raising prices to shore up profit on falling demand is a vicious circle, or at least it is when there's any competition at all. Sadly, that may be why Kodak can do it, but at what point does it get cheaper to import Fuji C41 sheet film yourself from Japan? Maybe it already is? (That's assuming it's still available - it was not too long ago.)
Most of the time when I shoot color in my 4x5 camera though it's 120 using a roll film back. The exception is that I have a box of Ektachrome 100SW I bought here that I've been shooting some of (not processed yet though) and if the scene demands a wider view than my 90mm gives on 6x7. I do have some Portra in the freezer. I have some Optima 100 too but I'd read it didnt' freeze well. I just shot a roll of frozen Optima 400 220 and the results were beautiful.