Well, it depends..some HP printers have seperate printheads and ink cartridges (this is my bailiwick, I work on HP printers 40 hours a week..well, much bigger ones, but I'm working on inkjet certs at the moment..;)
The current crop of 'cheap' printers are sort of razor (printer), and razor blade( cartridgess). I've actually ditched a printer (really cheap, under a hundred), because the inkjet cartridges cost more than the printer. In fact, I'm not sure about other vendors, but nowadays, they put chips in the cartridges themselves that communicate with the formatter boards, and the printer will 'honk' at you if you're not using 'their' supplies..it's a racket..;)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)