My sole concern in this case is gasoline.
No one has as yet explained the phenomenon of simultaneous price rise.
Not even sure the attempt has been made.
I know what you mean.
I’ve driven by several gas stations late at night and they all have the same price. Then at 5:00 AM they ALL have changed their prices, and again, they are all EXACTLY the same.
And there are variations within regions. Even with the same chain. Casey’s in the Midwest is the example I’m most familiar with since they are in almost every city AND burg. Yet they will have different prices if you drive any distance away.