Items I consider:
- is it on the way to work/on the way home?
- 24/7 (so I don't have to think if the place is open)
- # of pumps

Personally, I hate waiting (for anything). I will drive by the cheapies when there are cars waiting, and go to the more-expensive big boys.

Econ 101 in action...

I was going to add a URL to refiners vs. retail stations, but didn't find anything too interesting after a 30-second search. The cheapies have to buy their gas from somewhere.... like the same refineries as the big boys.

About the only difference would be if you argue that the big boys keep better care of their truck fleets, so fewer impurities make it into the trucks/valves/whatever.