From October 2012 to March 2013, the average weekly price varied from from $2.195-$2.319, or about $880-$1,050 to fill a 500-gallon tank; between 2005 and 2010, prices averaged $1.73-$2.66 a gallon, or $690-$1,070 to fill a 500-gallon tank. With three to five fill-ups per six-month season, total winter costs could be $2,000-$5,500.
Prices depend on the size of the house, how much of the home is gas-powered, and the climate, if heating is included. For small grilling and auxiliary propane tanks, expect to spend between $50 and $150. A standard 20 lb. tank costs around $35 while a larger 100 lb. tank costs about $150.