Thumb Score: +55 Costco Wholesale via Google Express has for it's Costco Members: Kirkland Signature Diapers (various sizes) on sale plus extra 25% off w/ promo code SHOPCOSTCO25. Shipping is free on orders $35+, otherwise is $4.99. Thanks rbusch6 Note, you must enter your Costco Membership Information (Name & Card Number) in order to purchase from Costco on Google Express.