Are you sure that the cartridges you can get "cheap" will fit properly?
It is possible, if you are careful, to remove the chip from an original cartridge and fit it to another cartridge if the necessary fitting posts are present. The chip must line up exactly on the replacement cartridge.
Don't touch the chip as the static in your body can zap it.
You will need a chip resetter to fool the printer into thinking that the replacement cartridge is full.