I agree with OP that we should try and buy Islamic books by authors who are still around and depend on the revenue from the sale of books. However, what do you say about books written by the past authors? In US the books published by IPH or Darrussalam is nicely priced, it will be hard to find a book under $20. For an average family its not easy to invest into a lot of books, therefore those interested resort to free ebooks. However, there are not many reader of these free ebooks as well, just look at the number of time any popular ebook has been downloaded, you will be surprised. Our Ummah is very busy ATM, it does not have time to read either science/math or deeni books.