Most of use know how expensive milk is. Then there is the maturing cow. He needs hay and grain every day to grow and thrive and stay healthy. You can feed hay alone if he is not a baby, and the hay is of good quality. It is better is there is some extra protein in it in the form of clover or alfalfa.
Protein makes meat.
None of these items are free. Then you will probably want to grow him for at least a year if you want a good sized animal to slaughter. That would mean about 4 tons of hay and about ton of grain. Then, after you have raised your cow, then you have to get him from hoof to freezer. Usually this means calling a custom slaughter company to do that for you.