That sort of thing happens with fresh produce here too. Some farmers deal direct with supermarkets and others sell direct to retailers. I live between two tiny townships 20km apart (on the edge of a vegetable producing region) and can see that sort of retail price variation between them quite often.
Big business will tear you a new one if they can. Your community, family or
single-owned business less so, as there is the risk of ostracism, shame and
why not, even a punch in the face.
Take Starbucks, for example. The cost of one cup for them is aaaaalmost the
same, no matter the product: regular, espresso with this and that, double shot
venti with pumpkin whatever, or foamy Kenyan roast a la creme oh la la. The
price they sell it to you, though, is abysmally different between one and the
other. It is a legal, shady way of asking each client: how much is the most
amount you are willing to pay for a damn cup of coffee. And people "tell" them
with their cash.