After going to about 5 different local, large chain office stores, Staples,Office Max & Office Depot and none of them having the Brother LC21BK Ink Cartridge for a fax machine, I decided to go on-line and buy it on E-bay. It was there, it was quick and saved money on it too! Only one of the chains seemed to even carry it but were out of stock at the time. The other 2 just didn't carry it anymore. I think twice now before driving around town looking for something that I might be able to pick up on E-bay.