Having extra capacity cartridges helps reduce the need to replace them as often. That said it would be cheaper to replace the entire printer than buy these replacement cartridges frequently. Certainly causing me to print less than before.
I paid more for the ink than I did for the printer! HP certainly a good racket going on here. I never remember paying this much for ink when I owned an Epson.
We buy and use only HP ink and toner in our HP printers. We have not had any problems with the quality of the HP ink. Even though it is generally more expensive than generic brands we will continue to buy HP ink.