Woot! Free Air!

The local dive shop in Pocatello has lifetime free fills if you buy the tank from them. Alas, there is no local place (within 150 miles) that will fill to 4500 psi. But, if you tune to a lower fill pressure, the SCUBA tank lasts for several fills. 

They also have a lifetime of free visuals too. The five year hydro test does require that the tank is sent out. But, the shop will give you a loner until it is returned.