one guy I know spent a couple of years doing a lot of printing, and simply bought a new printer every time the ink ran out, and threw the used-up ones away
I can't name names here here but my co. bulk buys badged low-end inkjets by the thousand. The purchase price is £23 and we sell them for £62, they ship with black & colour cartridges which retail at about £55 in total.
It's easy to see why people would buy a replacement printer just to get new cartridges.
What I would love to know is:
1. The manufacture cost of a typical inkjet
2. The manufacture cost of an ink cartridge/printhead