You're exactly right. With a few notable exceptions, fiction just doesn't do well self-published. With non-fiction, though, there are some nich markets that traditional publishers don't know about or wouldn't find profitable enough to pursue.
I would kind of like to get back into it, since it was my most sucessful eBay venture. You have to have the right product, though, and get good word of mouth from the hobbyists.
I'm actually thinking of writing up a family story-book: tales my father told my sisters and I as little kids, anecdotes about family events, and some history and geneology too. I'd be self-publishing that, of course, because it would not be for sale
I bought a self-published ebook off of ebay once, so I know that they DO sell. If you have something non-fiction (I agree that this is not the right market for fiction), eBay seems like a good way to sell it. Especially to a niche market.
I'm talking about hard copies. It is easy to become your own publisher. Just sign up for ISBNs (you don't even have to do that unless you want to sell on Amazon), print the books out and bind them some way. I got a manual comb binding machine for about $50 and printed my covers out on nice card stock.
Well, you can get all the equiptment yourself, or you could just pay to have multiple copies of your book bound and printed. Lulu (and others) are print-on-demand companies. That means that they only print a copy of your book when someone buys it. This is the cheapest way for someone to print a book because there is no outlay of money on the author's part.