Have you tried Ink Grabber??
Well...I'm going to give them a try today. I have the hp cartridges that you can't get refilled (although, I do tusrn them into Staples for the $3.00 rebate). The replacement cartridges are only $5.99 (for my printer anyway) and that IS far less than Target or Walmart.
Let me know if you try them and how you like them!