I think in an economic sense I estimate the amount of utilization more pizza will give me, and once I know how much costlier the next size will be per square in

I think in an economic sense I estimate the amount of utilization more pizza will give me, and once I know how much costlier the next size will be per square inch, only then I conclude if it's worth it or if "I'm not really hungry enough to pay _that_ much!"