[0815test]

> consider why skim milk costs LESS than whole milk, even though skim milk is more expensive to produce. ...

Isn't skim milk a side-product of making cream and butter, which is the "fat" part you mention? I understand your point, and the consumer side is definitely a factor in how jointly-made products are priced, but it isn't exactly irrational for it to cost less, even though it's made using whole milk as a feedstock.

[jkartchner]

No, I don't think skim milk is a byproduct of anything. With whole milk you can get whey and cheese. You can get butter and buttermilk. But skim milk has to be intentionally done. Im pretty sure.