Arlington is a funny town, they were also "dry" until a few years ago. Maybe it is conflict between some townies who want no change and newer people.

I don't usually buy gas in Arlington (though I have some family there), but I used to go through Milford a lot when they were no-self-serve, and the gas was always more than surrounding towns. OTOH I drive through Maynard some, and the cheapest gas there is the only full-serve station, so I don't know.