Some people prefer pre-bound books; other want to use looseleaf in 3-ring binders. Sometimes, cost-saving is the primary concern. If you wish to compare the cost of buying pre-printed books with printing PDF files do this:
Preprinted book cost = price of the book + shipping.
Printing a PDF cost = price of the PDF + cost of printing + cost of binding (if any).
To figure out how much it will cost to print the books from a PDF, multiply the number of pages (info included in each product description), and figure out how much it costs per page to print at home or at a copy center. All the pages are black-and-white; it usually saves some money to print on both sides. If you are going to use a copy center, call ahead to confirm pricing.