I also have a HP printer. We have a Staples Office Supply store in Prescott, about 20 miles from me. Staples has a rebate program where I can return the empty cartridges and get a $3.00 credit. When I'm ready to purchase more cartridges, I go online and print off my rebate and take that to the store to buy more. Their price (without the rebate) is the same as Walmart.