This strikes me as the same sort of semantic game one plays when claiming that "humans are actually fish"; while technically true, this drains the term of its utility.

While I take your point about economy, in my kitchen it would actually take less time to make a cake from flour, sugar, butter, and eggs, because we always have them - whereas buying a Betty Crocker mix would require a trip to a grocery store, and not the convenient one around the corner I usually visit.

Nor are the results entirely fungible: I'd always prefer to avoid ingesting preservatives, artificial flavors, corn syrup, etc.