Most self publishers don't go to the bother of creating a catalog simply because they haven't written enough books to justify it. Not producing a multitude of related titles is a serious weakness in the business model of many self publishers, myself included. I can attract a large number of visitors to my website for the different subjects I write on, but for the main part, those visitors aren't interested in my other books, since all of them are niche titles.
A savvy business person would seek to "monetize" all of those visitors by presenting them with other related products to purchase. If I hadn't intentionally cut way back on direct sales of my own books a couple years ago, I would have set up a bookstore of related titles to sell direct by now. Titles from the big trades are available at a deep discount when you order them direct in quantity, you might get 65% off or more if you agree to take them on a non-returnable basis. So if you can find some relevant titles with decent cover prices, in the $25 to $40 range, you may find you can earn more selling those books than your own!
A much simpler and less risky way to make money selling other authors books is to simply add Amazon Associates links to your website. You'll only earn a dollar or two on most sales, but you'll learn quite a bit about what your readers are really interested in. For example, I'm going to put in Amazon Associates links for some of the books I often mention below:
Note that Kirsch's book was due out yesterday, they just haven't posted a cover image yet. And that's about as lazy as I get when it comes to writing a blog post, but I've got to make some dinner and run out!