Yes - and the 1/8 of a cow is needed to make milk to make butter. This might be possible if you were very selective about which eighth of a cow you procured, but you’d need some additional kit which the recipe doesn’t account for.

Some of the $0 items are the base "from scratch" items. You can click on an item to make it from scratch; doing so for eggs gives an egg-laying chicken (with an associated price), but doing that again gives the base level of "baby chicken." Not everything goes down that far (e.g. baking powder) but things like soil and seawater are of that ilk. See also: vanilla