Common practice unfortunatley .
Bought a Lexmark wifi printer recently to replace a Dell that was just too expensive to run.
The Lexmark unit has proven to be more expensive whether it is printing on OEM cartridges or AN Others off E bay . The printer cost a paltry £65 (delivered ) to buy and the 4 cartridges required cost about £40 to replace and last no time at all.
Both can be filled by the likes of " Cartridge World " but the irritating warning box will often come up stating reserves are low, they will print but experience has shown that they don't last as long as the initial cartridges and the print quality is reduced.
I also have a large professional HP printer that was bought for the business & cost nearly £600 about 6 years ago . It has printed countless docs and many photos and is still on the original cartridges , so it can be done by the manufacturers.
I'm going to fit a wifi conversion to the HP and bin the Lexmark , Dell and another two that are up in the loft ........
As my old Dad used to say " you buy cheap , you buy twice ".