I can't help but get the sense that your economic materials analysis is based on a video game crafting economy. If the profitability of leather is low enough, then people will trash the raw hide but butcher and sell the beef. There's a lot of labor and logistics and materials that goes into producing the beef you cook or leather goods you buy beyond (cow) -> (meat,leather) -> (food,clothes). Remember, nobody knows how to make a pencil.