I sold around 300 in my first year (which ended recently), which is much less than the other book I wrote via my publisher. Yet, even though it is sold at a lesser price, my self-published book made almost more money. This is essentially because the percentage I make on every sales with my publisher is really low (10%). So for my next book, I'll self publish as well.

(the book btw https://securityhandbook.io/)