So, back to plugging away. The above table includes those items that might be obtained from a book printer, or bookbinder, using a printing press. The press can be employed for printing purposes, such as the pamphlet or the playbill prices above. These are the minimum prices for said items; it bears little value to the printer to set up his or her press for the purpose of printing only one page, so even if the character only wants one page, the full price for 10 or a 100 pages must be paid.
Spellbooks are necessary for mages and illusionists in my world, and are limited in how much they can hold. A first level player can usually get away with the apprentice's spellbook, though they may need two to start if they have a great many cantrips. This is the moment that someone steps forward and points out that 8 apprentice spellbooks are a bargain compared to the one large spellbook; my answer would be that it is easier to keep one large spellbook from falling into the hands of thieves than eight little ones; alternately, the large spellbook has a better saving throw against fire or other attacks, since the cover is heavier and more protective. In any case, I perceive a typical mage sitting down with various spellbooks, all locked together in a box or tied together with string or ribbons, poking through the various books to find the necessary spells, gathering books as the player increases level. The larger books become necessary when higher spell levels consume more and more pages.
There are a number of holy books listed here; obviously these work in my world but probably nowhere else. They are measured according to the size of the actual book based on the total number of words known to make up those volumes. Many might find it odd that the Koran is quite small compared with the Bible. I confess, I did not make allowances for the Koran to be written in a different, paper-using language; I only have one language in my world, so in my world the Koran is written in common. They may seem less Romantic, but I am lousy at other languages than English and I'm not interested in the playability aspects that come from a lack of communication. My game style depends on much communication and so that is how I play the world.
The various book forms, common, unusual, rare and arcane, are part of the sage's system I use which indicates the likelihood for some piece of knowledge being known about any part of my world. The more books you amass, the greater that likelihood; unusual books have more knowledge value than common books, rare books have more than unusual books and arcane books have the most knowledge of all. The sizes and number of pages of these books should indicate the total volume of knowledge contained within.
Books make treasure, too. A library of two or three thousand common books would make a fair haul .... if they could be hauled.
