I cannot figure out why teachers keep doing this-if the school system has a curriculum it seems incumbent upon the school system to provide the things that are needed.  I loathe unions but in many States there are teachers unions.  In my view the union-where applicable-should take this up-teachers should simply not pay out of their pocket for anything.  I have no sympathy therefore when a teacher makes a decision to expend money for items they think the kids need.  I pay a bunch of money in school tax and in my view the teachers open themselves up to this-once they start-it will not stop-so quit doing it and figure out how to do it with what is provided or quit teaching.....Have a nice day!