We have an old HP Deskjet 970Cse. Printer cartridges are amazingly expensive at $25 for large black (45A) and$50 for large color (78).
"Omnipro": http://store.omni-biz.com/. Trying a place that sells remanfactured cartridges for $10 and$15 respectively a pop. A little bit of a risk, but interested to see what the quality is like. Got good reviews at Yahoo and Pricegrabber.