Budgeting: The book problem

I have decided I need a book budget.  Just this week I have purchased over $200 in books; most of them are for school, but a few are for pleasure.

I guess it isn't surprising that spend so much on books, as I have always been a reader.  My aunt would punish her daughter/my cousin when I was at her house by ordering us to my cousin's room.  As we headed upstairs, the last words were, "And no reading any books either!"

Right now, I have a shelf of books that I want to read.  I occasionally pull one off and read it, but with my school schedule, it rarely happens.

So, now I need to come up with a reasonable amount budget.  Maybe a hundred?  Fifty?