Most of the people I know who sat those exams (Including me) borrowed the books from friends.
It does cost a lot of money to purchase these books. I recommend you buy the Full AIP books DAPs/ ERSA/ AIP (or Jepps) because if your flying IFR you well need them. You can always look-up CAR's, CAO etc on the net for free, and be fairly safe in the knowledge that it is up to date and correct.
