I've got a Dell basic photo printer -- their price is around $28 for the black ink. My parents have always had extra, I've never had to get it!
I saw some "refurbished" ones but don't know if you just take your chances. When ordering school printers, those generic ones that are supposed to fit the printers often don't.
I could check e-bay -- anyone else have a good place to order less expensive Dell cartridges?