(I know it's an old thread, but still relevant.) Re toilet paper... That's what all the ruined books are for, and why they're worth so much! Sure, you can use them at the Atronach Forge, too, but only to make a couple very specific spell tomes -- how many of those does anyone need? That woudln't explain why they're worth 5g apiece. Or why there are so many of them kept all over the place. Use as toilet paper would explain it. When a book gets ruined, you wouldn't throw it out when it has such a needed use.