Books, more books, and even more

The book " Introduction to Number Theory by Mathew Crawford " is on sale for 20% on Amazon for $166.68 (Hardcover Version). Delouf wants to buy the book, but he's been running short on money recently. By some god-given miracle, he finds a free version of the book online, all 314 pages! However, because of convenience issues, Delouf wants to print out the PDF version of the book from online. So, he goes to the printing shop. He knows it will be much easier to print 314 pages, rather than to spend his whole life-savings account on the hardcover version of the book. When Delouf goes to the shop, he finds out that they charge $0.05 per page. Because delouf doesn't want too many pages, he wants to double-side all the pages. Delouf finds out that there is a range fee. If the price of printing (WITHOUT the double-sided fee) is between $3.00 to $8.00, the one time double-sided page fee is $2. Between $8.00 and $13.00, the fee is $3. Between $13 and $18, the fee is $5. Delouf finally finishes printing, and pays all the money. How much percent of money has Delouf saved by printing the book instead of buying the book at full price (without the sale)?