It kind of makes sense as cheaper products are less "organic" and treated with cheaper/worse chemicals.
And, there tends to be more packaged foods in these places, rather than "close to fresh".
I (for better or worse) eat a lot of nuts and I have always found it interesting that salted nuts are cheaper than natural. Doesn't that require more processing?
Salt makes them last longer I think ;) or maybe allows them to use lower quality nuts as salt will kill the taste🤔🙃
I would go with the lower quality nut argument - that is what I have assumed :)
One interesting thing here is unsalted butter is twice the price of salted. However, they have the same shelf-life! :D