Although today many people say table scrap is not good for pets, people had been feeding their dogs and cats with table scrap for centuries. Basically they were eating what humans eat, but the leftover. If that is your idea of "cooking for pets", then it is cheaper than buying pet food for dogs and cats. If you cook just for the dogs and cats, it might not be cheaper than buying pet food. Since most likely you will only be able to find human grade ingredients on the food market. They will cost more than pet food with lower grade ingredients bought in bulk by pet food companies.