I suspect a major part of the Arizona cost is shipping.

Something I've noticed is none of you are talking about delivering based on usage.  We (and the reputable companies around) route "courtesy fill" customers on the Degree Day system.  You have a system in place that estimates demand and use and gets you back to a customer when the tank is at a certain point (we prefer 20%).  It doesn't always work perfectly, but it generally works pretty well. The biggest problem we have is extreme temperature variations and high wind ... which pretty much describes the winter we've had around here.