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.

Just got a window air conditioner on the Costco web site, delivered to the home. That was 25% cheaper than in the store.

But saving the cost and time of you driving there yourself, which if you're honest is probably worth the delivery fee.

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.

Sure, although personally the comparison would be to delivery from other stores.