Our school always goes through its budget for discount office supplies quite quickly. In fact, our last order included A4 paper, hand towels, a printer cartridge or two, and lots of ink for board markers. Typically, we order once a month for our supplies.
Though our office supplier offers food items, we never order them. I did compare prices for tea and coffee, but I just didn’t find anything that I reckoned worth buying. Still, one day they may actually stock decent coffee. Who knows?
But there are several things I like: delivery to our order (esp. for bigger items), bulk purchasing, and next day delivery! Those are compelling enough for me!