II have never NMC of modern construction chewed by rodents, the old stuff yes.

Cost, yes, I do not see prices that often but I think NMC is 1/4 to 1/3 the price of MC
I am sure someone here could be more accurate with price. You can install it much faster; use plastic boxes if you want.

But I would rather use MC in most applications


Bob Badger
Construction & Maintenance Electrician
Massachusetts