So far, the figure is not zero but it would be if I valued my time at minimum wage. I did earn back my first print costs and more, but I used the earnings to fund another print run, so….
But my point in posing the question is to say that the real answer is based on another question…
“How many books can you sell?”
If you can sell 100,000 books as a self published author, you can make a decent living with even a crappy paying distribution channel.
But most books don’t sell 100,000 copies. Most books don’t sell even 2,000 copies.
As a self published author, you will receive payment on as many books as you sell.
Therefore, how much you can make depends on how many books you sold and how much it cost you to produce them.
The amount of payment you will actually receive depends on how that book sold. Each distribution channel should tell you up front how much it will pay, and it depends on the book’s retail price, and the kind of account you have with the distributor. The payment is often called a royalty. You may not feel like you have a book deal with a publisher, but you do. Your publisher is you, and the royalty deal you got is anywhere from cents per copy to dollars per copy.
But before you “make” any money, your publisher is probably going to require you to pay back the book production cost. Publishers are just weird like that.
So sky’s the limit, right? As a self publisher, you are free to hit it big or quietly starve. You can make nothing as a self published author most easily. Or less than nothing, because you will incur some costs in getting set up. Or you can make a full time living as a self published author… people are doing it. But there’s a reason for the common term “starving artist” and the new eBook dictionaries are starting to show pictures of self publishers under the same heading.
Just kidding, but still… it was one of those kinds of questions.