We have a budget for consumables here at £8,000. Out of this budget I buy CDr's, Floppy Disks, Memory Pens, Toner Cartridges, Ink Cartridges, Drum Units, and the copier paper for the whole school.
There's about £2,000 left which isn't too bad since i generally buy a lot of stock in at the start and still have a lot to use up. If a department has a printer in a room that only they use i.e. not timetabled for any other lesson then they purchase the ink out of their own capitation.