An interesting article on Linux.com listing the possibilities available to check the ink levels on different printers under Linux. It is very handy to know what is left in a cartridge before you start a print job, so you can NOT start the job if there is a risk of one color getting short (and you lose the print).
libinklevel is available in Ubuntu repositories but only 2 frontends are available: qink (QT4 based) and a command line: ink. It looks like my printer is not supported, so I cannot tell you more
A funny line from the last Chasseur d’Images: 71% of the people interrogated in a survey from Ipsos-Kodak stated that price of ink for printers is far to high. Among them 39% stated it is a “robbery” (arnaque).