Teardowns of accessories tend to show that to be true. Any similarly built product tends to cost even more thanks to Apple volume.
http://www.righto.com/2015/11/macbook-charger-teardown-surpr...
And this tiny thing proves to be labeled 40W while actually delivering 60W safely which is nuts:
https://appleinsider.com/articles/25/09/17/custom-chips-and-...