The Ancient University and Distance Learning: A visit to the Getty's manuscript collection revealed another unexpected expense, sheep. Sheep skins for parchment or vellum were used. One sheep skin could be used to make approximately 4 pages for a normal sized book. So a 400 page book required 100 sheep. There was a short explanation for this dependence on parchment attached to the display which attributed it to the fall of Egypt to the muslims and the consequent blocking of the papyrus/paper trade to Europe. Combine all these costs (and I thought a book took a year's labor), and each book's costs were probably equivalent to the production of a movie today. So if you see it like that each book purchased meant purchasing a large flock of sheep and the services of highly skilled labor for a substantial mount of time, you certainly needed to share. How dull that course instruction must have been.