Most books are not commodities like lumber, copper or sugar. Books by different authors, about different subjects written for different audiences are not interchangeable. Shoppers probably don't compare the number of pages per dollar or the number of hours of pleasure provided by two different books and pick the one that provides the best value, like Happy Meals at McDonald's vs Kids [sic] Meals at Burger King.
Nevertheless, it's very important for a publisher to consider the prices of other books aimed at the same audience when putting a price on a new book.
The two books above are aimed at different audiences (I may be the only life form in the entire Milky Way Galaxy who purchased both). However, both books are non-fiction and may be used to educate readers to help them make money -- so a comparison of the books can be useful.
If you look at the numbers above, it's obvious which book is a better value. This doesn't mean that the book on the right is better than the one on the left, but it does show which one gives more for the money. If you compare page size, color vs. B&W and binding, the difference in value is even stronger.
As a publisher, you have to figure out the perceived value of your book. If most of the competitive titles are selling for $12.95 - $14.95, you'd better be very sure you can justify a $19.95 price and that potential shoppers will understand the difference and can afford the extra dollars. If not, keep your price in line, or even go low if you are trying to establish your “brand” and think you can attract buyers with a low price.
On the other hand, some books can demand higher prices.
If your book is vitally necessary for business or government, and doesn’t just provide entertainment or casual reading, a book that costs $4 to print could bring $29.95 or even $75. If people can be convinced that your reference work or new theory will save them or make them many times the investment, there is really no limit to the price it will bring.
Just keep in mind that at a certain price point, the book has to look better physically, and probably should be hardcover not a paperback, and have multiple strong endorsements (”blurbs”) from experts in the field.
I've previously written about the low profit for an author caused when a self-publishing company dictates a book's retail price based on the number of pages in a book without considering prices of competing books or the perceived value of the new book. Unfortunately, authors who have the freedom to set their books' prices can cause even worse trouble for themselves: very low sales.
It's important that authors write books they can be proud of, and that authors be proud of their books. Unfortunately, some authors seem to have too much pride. They have an unjustifiably high opinion of their work and their position in the marketplace. The authors set prices that are so absurdly high that sales will be hurt.
Hmmm. Is it a coincidence that all three of the high-priced books were published by inept Outskirts Press?