Every inkjet printer runs through ink too fast and has refills that cost way too much. It's the business model.
You have a few options.
1) Suck it up. Deal with the fact that every time you buy new ink it costs almost as much as buying a whole new goddamn printer.
2) Refill your ink cartridges yourself. Staples in particular sells these nice refill kits that basically just come with three bottles of ink and a syringe. It's easy as hell with some carts. Don't buy refill kits from Wal*Mart, they only sell these shitty things with squeeze bottles that spray ink all over your hands and table and everything.
Note that print quality will steadily decline as your print head wears out. Still, can't beat the price, and it's always nice spending like 90 seconds injecting ink into a cartridge and realizing you just saved thirty bucks.
3) Bite the bullet and buy a laser printer. Newegg sells a decent color laser printer for like three hundred dollars. Toner drums may look expensive, but a $70 toner drum will last like two years, as opposed to a $15 ink cartridge that lasts a week. Do the math.
Also, your print quality will be phenomenally better. You may have noticed by now that inkjets warp the paper if you're printing anything more than like 15% ink saturation and not using special super-expensive photo paper. Lasers don't do anything like that. But it's one hell of a startup cost.