Yep, around 18% higher not including tip, in my estimate. HEB (local Texas grocery chain featured here a few days ago) puts in just a 3% margin for pickup or delivery (before tip.) Walmart and Sams have no special delivery/pickup margin but instead charge delivery fees that can be avoided by membership levels or order amount thresholds.
There's free 2-day shipping from Costco for purchases over $75 (at least in Seattle). It's not hard meet that requirement. Right now, I only tend to go to Costco if I need to buy refrigerated or frozen items.
“costco delivery” is basically amazon with a higher minimum spend and no perishables. “costco same day” is delivery costco via instacart, with adjusted prices. i use costco delivery a lot because a good portion of what i buy there can be delivered with it