Once a year, crayons and glue become unbelievably cheap--often 75-90% off their regular price, even for the good brands!
Right now at our WalMart, boxes of crayons are $.25 (Crayola) or $.20 (a new brand called Cra-Z-Art, which Anda and Dan tried and said they like better than Crayola). Glue is similarly priced. Notebooks are $.10-$.15 each, depending on which store you go to. Pens, pencils, notebook paper, printer paper--all on sale dirt cheap.
So stock up once a year. None of these things go bad!