Costco staples aren't necessarily
your staples; there are certain products that Costco has continually had in stock for more than the 20+ years I've been wandering the aisles in search of the Arc of the Covenant (I'm certain it's somewhere in there).
But other things that look like stapes can come and go, some seasonally, some after a few years.
Costco is a very "go first" store - you go there, get what you can, and then flesh everything else out at some other store that will keep things in stock even when they get pricey.
Costco is also not the cheapest, not by far, but they are the most consistent.
Butter and soda are two of the most noticeable for me, you can easily beat Costco on both, butter because local producers often supply local stores cheaper, and soda because it's a loss-leader in many places. There are others, find them!
But other things that look like stapes can come and go, some seasonally, some after a few years.
Costco is a very "go first" store - you go there, get what you can, and then flesh everything else out at some other store that will keep things in stock even when they get pricey.
Costco is also not the cheapest, not by far, but they are the most consistent.
Butter and soda are two of the most noticeable for me, you can easily beat Costco on both, butter because local producers often supply local stores cheaper, and soda because it's a loss-leader in many places. There are others, find them!