Pin It As a new mom, I am still surprised by how much diapers cost. However, COSTCO has put my mind at little more at ease. If you buy COSTCO's brand (Kirkland) diapers you will save yourself some money. A package of 216 size 1-2 diapers cost me $29.99 while at Walmart, a package of 168 size 1 Huggies diapers is $39. I have used both Kirkland and Huggies size 1 diapers both and have actually had less blowouts with Kirkland's.