Lexmark has insanely expensive ink
The razor blade business.
Not only are Lexmark cartridges expensive, but the built-in heads are not designed to withstand refilling. I've ordered a few 'remanufactured' (refilled) Lexmark cartridges from a few different places and the results are always crap. Ink heads have clogged/non-functioning nozzles, constantly drying up if you don't use them for a couple days, requiring you to remove the cartridge and 'clean' the print head manually using a moist paper towel. So I've had little other choice than to buy a new cartridge each time.
The next printer I buy will be a Canon. My sister has a BJC-4300 that is four years old now and she replaced the heads once, the part was like $40.00. She prints 2x as much as I do and probably has spent half as much on ink.