I accidentally did that with Walmart.com once. My bill was $40, which qualified for free shipping. I checked out, and realized that I had ordered one of the items (about $20) to be picked up, which wasn't possible because there's no Walmarts near me. I quickly canceled that item, but the rest of the stuff shipped.

I kind of felt guilty, because I genuinely wasn't trying to game anything.

Whatever trust and sense of ethics there was have been swept away by companies playing continual pricing games, eschewing quality assurance, and nickel and diming workers into doing the bare minimum. Personally I'd love a store that had consistently low prices where I could save money by batching orders for different things, packed items well, had intelligent empowered customer service, and charged money for elective returns. But evidently there is more money to be made by confusing the market with wildly variable prices day to day, price fixing across stores, and turning the screws where they can. The industry has made it clear that the only thing that matters is the formal terms, so that's the game I'll play.

For example, I've got zero qualms about buying something I merely might want because it's a on a good sale, and then making the actual decision over the next 30/90 days. And if I've already got a pending return somewhere, then doubling down with more speculative buying is essentially free. Holiday shopping season is basically an extended project season.

Or when items arrive damaged, I'll optimize the presentation of my complaints such that I'm less likely to have to actually return them to get replacements. This saves me the time of doing so and makes up for having to deal with the situation in the first place.