There are a lot of costs associated with a project like this. If I self publish the printing will set me back ~10 grand. Shipping books, promotional costs, shows, and PR all cost something. That's not including my time to make the book.
I do well in my career, so I'll cover those costs. I'm perfectly willing to pay for all it because that will give me the most flexibility and control. When it's close to done, I'm going to pitch it to some comic publishers. If I can get a good deal, and still retain the overall rights I'll do that. The benefit of that, of course, would be that they would absorb the cost of printing, but more importantly they would have major distribution. I don't have that ability myself. The more shops stock the book the more potential for sales of course.
There's a saying in Hollywood that I love, "Never spend your own money." π