For anyone interested in the average profit margins of books publishers and some what the percentage of the paper, print, and binding for a book is of the total cost, the Art & Science of Book Publishing by Herbert S. Jr Bailey (http://www.amazon.com/gp/product/0821409700/ref=wms_ohs_prod...) is a good book. Print on Demand and ebooks have changed some aspects, but it is still largely true that, for most books, marketing, overhead, sales, etc. are a lot of the cost of producing a book. Even with ebooks, this is still the case. Illuminating stuff.