This statement is surprising at first, but if a book fulfills some parameters, it could easily be true.
One of our clients gave a 240-page, illustrated technical book with pictures, which very quickly required 500 printed books. He brought the material in Word, with the average layout that is available in Word. The book was printed, but we talked over the author that it would be good for the publication to be redesigned.
Fortunately, the book sold well, so the author ordered proofreading, designing, and printing for another 500 copies. We did not change the size of the book, the font size, the size of the images, "just" in InDesign, we created a new edition with the rules of the layout design.
The consequence: The 240-page book became 170 pages. We managed to win exactly 70 pages without wanted to do it.
What did all this mean in money? Printing a new book with layout designing and proofreading was cheaper than printing an old book without designing. So if you have a book of which you want at least a few hundred copies and the book contains not only textual but also pictures and tables, don't hesitate to order it, it will come out cheaper than without it.