Can't help with cheap cartridges, but I can say this. Epson have cheap cartridges, while most of the other brands don't. I looked into this and found out;
Epson have the jets as part of the printer, while the rest have them as part of the cartridges, so when you replace your Canon cartridges for example you are getting brand new ink jets. Also Epson's ink monitoring is very very basic and works on time and number of printer start ups rather than actual ink levels, this is so the ink jets don't burn out if the ink runs out. So the consequence of this is that with Epson you quite often have to replace cartridges that have 50% or more ink in them. You can buy a little widget that resets them to fool the printer into thinking its a new cartridges, but be careful not to run out. When you buy a new printer you rarely get full cartridges.
So in short, that's why cartridges are so expensive. Don't buy an Epson if you do very little printing and you don't have the widget to reset the cartridges.
Agree with stew-b though, laser is the way for value for money.