Well, if you're wanting to minimise print costs, stick to printers
that have single ink cartridges (inks NEVER get used at the same
rate) and pick one that actually measures the amount of ink left,
rather than relying on a chip to count the number of dots - these
typically overestimate the amount of ink used quite substantially.
Never mind how much ink goes into each cartridge, look for the ISO
ink yield figures - this is a standardised procedure for measuring
ink yield, and is pretty robust. Then look at the cartridge cost.
That should tell you a cost per print - which is what we're after.