Costco Grocery: $20 credit toward future purchases by spending $100 or more

Spend $100 or more on sameday.costco.com and receive a $20 credit toward future purchase on sameday.costco.com
Valid 10/13/20 ~ 10/16/20 | Limit 1 per Member
checked the listing and the price seems quite comparable with my local warehouse, searched and it’s not posted, delivery tip is around 5%
https://sameday.costco.com/store/…storefront