In his teardown, [Ken Shirriff] thoroughly investigates and describes all of the components and circuitry that go into the ubiquitous Macbook charger. Why does it cost $79? Other than the MagSafe ...
If you're opting for the more up-to-date designs of the 2023 MacBook Pro 14-inch then you'll also get a 67W charger in the box, while the 16-inch model comes with the top-end 140W charger as standard.