I got a message to replace my CYAN cartridge on my printer last month, then printed 45 more pages with blue on them until it got so light I really needed to replace it.  Usually I just use it until the printer refuses to print until I change it.  To me, it’s not about being cheap.  It’s about making the most of my resources and not being wasteful.  Like I used to glob toothpaste up on my brush because that is how I grew up seeing them do it in the commercials.  One day a friend mentioned I sure wasted a lot of toothpaste and from that day forward, I use just a pea size, not a brazil nut size portion to brush my teeth.  So don’t let society – or commercials on tv – tell you how much product you need to buy and use.  You can get more brushes out of a tube of toothpaste.  You can get lots more pages out of your printer by not replacing the ink cartridge at the first error message telling you to do so. I think of them as suggestions well in advance.