If instead the 2 gas stations were both selling at $4.45 and looked around and decided not to lower their prices to $4.15 even though they could, it's equivalent.
I don't have a source for this, so take it as you wish, but as I remember what I read, duopolies can be quite stable. Three party cartels can go either way.
But with 4 or more participants, someone will inevitably betray the others out of greed.
