A couple of other types of photography in printed form that may be less expensive and still not encounter the Library of Congress and ISBN number considerations are calenders, posters, postcards, and notecards.
About 20 years ago I produced a composite image that I copyrighted through actual governmental procedure (aside from simply afixing a copyright notice to the work). This image then became the basis for a poster that a graphic artist designed the layout for. I worked with a printer in the color separation process and the matters of paper choice, varnishes etc. I produced 5000 of these (at that time) for a cost of $5,000. I took care of the distribution myself (what a pain). I sold the poster to the retailer for $15.00 which they in turn marked up to retail.
I would think that high quality posters (both of image strength and also printing process) would still work today. Additionally high quality note cards and calenders may work as well.
This makes a photographic image available to a greater potential audience since the pricing is more favorable then an actual photograph. There is a segment of our population that simply want something attractive hanging on the wall. (they don't really care that it lasts 25 or even 100 years longer then their lifetime). I would guess that their numbers far exceed the true collectors of photographic art.
The matter of distribution would still be a matter of concern and consideration. Those details would need to be worked out.