Payment for using library

Hi, in Covenants, it's mentioned that a payment is usually given in return to being able to study/research etc in a covenants library. I'm -sure- it's detailed more firmly elsewhere.. but can't find it.. .. anyone know off hand?

Thanks

Guardians of the forest give some guide lines for Durenmar....I want to say standard is 2 pawns/season to rent a lab not sure where thats written though, since the order is supposed to share knowledge I'd assume that includes the use of the library

House Bonisagus is supposed to share knowledge. The other houses will occasionally get stingy.
If you're just researching in the library it's probably safe to hand-wave the payment, or make it storyline; it might be "fifty pence a day" but who bothers keeping track of that? If it's Vis, make sure you're getting a good value; the books should be rare or valuable.
That's assuming you're reading. If you're actually copying, you're probably expected to provide an equivalent text; Covenants 95 has some rough guidelines on this.