alt Hacker NewsCostco is not for everyone, though. I really can't use it for most of my shopping because it's just me and my wife and she won't commit to eating something specific for a week, but "meals for two, to be decided upon at 5 pm daily" doesn't fit well. We don't eat a lot of the staples they do have that are shelf-stable, and their freezer packages are big enough that to have any variety I'd have to not only like what's on offer but buy a chest freezer that I don't have a good location for.
The stuff they have is nice, but unless I'm going to go buy a bunch of steaks or something, it just barely pays for itself if that. I've let my membership expire and renewed when I had something significant to buy (in which case it's definitely worth it). For my life, it's cheaper to buy smaller packages of the things that will go bad like meat and produce, even at a higher per-unit cost, and it's much closer.
Now, Walmart Plus? THAT has been fantastic. It pays for itself quickly because they will deliver the items to me for the staples they have, and I only have to get one loaf of bread, one small jelly, etc. I don't have to drive out there, walk to the back of the store, pick out one size of paper towels, go pay for it, and drive home again. It's easy to put together a $50 order to get free delivery because it's all my staples in quantities I'll use, not only one or two in family-of-four quantities.
We (the two of us) do fine with 95% Costco shopping, and I have similar "she won't commit to eating something specific for a week" restrictions. The only real tricks are get better at storage[1], and get better at cooking[2]. FWIW, the 2% rebate on the executive membership always covers my membership renewal price plus $50-$100 off a shop.
[1] Yes, you need somewhere to stuff 24 rolls of paper towels etc. I ended up building more shelves in the voids at the top of closets and the like. Ladder-access only but it works out.
[2] Stop doing 32-ingredient cooks with baby bok choy and white tomatoes and whatever other exotic instagram reels crap. Buy beef, chicken, fish, then portion and freeze (a vacuum-sealer is not necessary but it helps). Buy a standard 4-5 vegetables and a couple fruits. Potatoes and rice for carbs. Then figure out a list of recipes you can make from those ingredients -- I promise they can be combined damn near indefinitely.