I've noticed that the ink cartridges for many of the older models of printers such as Epson, HP, Lexmark are extremely expensive.
Perhaps this is a ploy by the manufacturers to get people to buy into the newer models. The original cartridges for many of the newer models are a lot cheaper - however I would still look for the cheaper compatibles online.
Printers are not expensive, it's the inks that cost the money.