500 Gallon Propane Tank
It is significantly less expensive to go with a delivery service in Missouri as opposed to refilling yourself. Here is the cost structure for leasing a tank:
Ferrelgas - 816-232-3705 500 gallon tank lease: $45 (1 year, first year free) Setting & connecting tank + safety inspection (incl first 50 feet of gasline): $149.95 200 gallon minimum refill (prices fluctuate): $1.449 per gallon
They refill your tank at 80% for safety reasons, which brings a full tank to $580. They also offer a keep full service to keep track of your tank and refill when it hits a certain amount. The service is free of charge.
There are smaller options for tanks, but they are not cost effective. A 250 gallon tank is $75 per year and the first year is not free. They do this because it costs more for them to come and refill smaller amounts more frequently.