We knew printer ink was expensive, we just never bothered to put it into perspective before. And now we don't have to, because somebody else already did, and the comparisons are pretty eye-popping.
In a graphic comparing the "relative price of different liquids," a single mL of HP black ink #45 runs about $0.70. That's nearly twice as much as a mL of blood, which according to the data runs less than $0.40. It's also almost 14 times more expensive than Penicillin, which runs a little over $0.05 per mL.
So there you have it. Assuming the numbers are accurate, penny pinchers may be better off pricking their finger and refilling those empty ink cartridges with their own blood (please don't try this). Of course, there's always generic ink, which while usually significantly cheaper than "genuine" ink from the printer's manufacturer, have also been known to clog print heads.
Have a favorite generic ink manufacturer/vendor? Post a link in the comments section below.