Butchery is a HUGE topic of study. You would have to study for years to learn all there is to learn about butchering. Not always a practical thing to do, but knowledge of butchery WILL definitely save you money and time. If you buy a cut of meat that has been cut buy a professional butcher, you’re paying for his wages – simple. If you buy a larger cut that has not been ‘finished’ by a butcher, then you will enjoy a savings. The same principle applies to fish. If you buy a whole fish, or catch one, you will save significantly compared to the price of buying a ‘finished’ fillet of fish.