Don't laugh, have you priced HP ink cartridges ?
The ones I've needed for almost a year are $50 each.
No, I'm NOT going to pay that.
What really honks me off is that HP seems to have drunk deep of her kool-aid, and the cartridges got smaller while the price per ml went up. I had one printer that used 19ml cartridges - the black ones were about $22. The printer eventually gave up the ghost after a long time, and the new one uses cartridges that are 5ml - at $16 a pop.
I now order from cartridge pros online, they have the higher capacity cartridges.