Dude, I had a 940c for years, I just gave it to my dad when I bought a laser. Great printer.
Buy the ink on ebay. I would buy 3 packs of the black for like 10 bucks, and the color ink was 2 packs for like 15 bucks.
Get a remanufactured cartridge, don’t waste your time refilling them, the print quality goes right to shit when you do that.
A bunch of companies make generic reman cartridges and they are better than oem because the tanks are full versus buying a genuine hp cartridge that is half empty.