My local rural stations (the type with pumps with scrolling numbers from the 1980s, tiny shop, branded PACE or similar) always seem to be super expensive - preying on convenience and the "local" service/empty/easy forecourt. There is one in the next village to me, absolutely ancient looking place, now firmly up over 150ppl. I guess ultimately the price doesn't matter to a lot of people who do low mileage locally.
In general they are always more expensive than the big petrol stations but even last week our local one was posting on FB that they had fuel and also they were the cheapest in the area for 30 miles and cheaper than the big supermarkets - until they ran out 2 days later and then when the new stock came had to put their price up above the supermarkets again.
I didnt see it as "preying" more to do with just plain simple economics. Buying one tank of fuel a week means they will have to pay more than the supermarkets do who will go through millions of litres and more buying power.
I used to work for a haulage company and once we got big enough - 180 trucks, we were allowed to go and get our fuel direct from the refineries and miss out the middle man as we were using a full artic every couple of days or so. That was several pence cheaper than what we had been paying.
Plus there overheads has to split over 25,000 litres of fuel sold in a week/month whereas the supermarkets might be doing that per day.
Its like when people used to complain about the prices in corner shops where the owner will have gone with a van to the cash and carry every week to stock up and paid more for cornflakes than what the supermarket sells them for and then people wonder why they are even more expensive in his little shop.