You can add dollar general, dollar tree and other low end retailers to that list.
I would say the above may be better indicators. I’m my area Walmart looks high end to dollar general.
Dollar General is not cheap, it is handy. For me I can make a 30min one way trip to a "real" grocery store, or 10min to the $ general. But the prices at the $general are always....as in ALWAYS higher and in most cases smaller. If we need something right then we have few options.