I will name a couple places.. ONE by name, one by location.
Flint, MI.. Parker's Propane, Carpenter and Dort Hwy... That's where I just filled my Class A. Cost me less than 30 bucks for 19 gallons.
The Bulk propane wholesale place in Seneca, SC.. AVOID.. The Hardware store which is ALMOST across from the Wal*mart (Few yards farther west) is way way less expensive.