If ya HEAT with it ( and run appliances, waterheater, etc....)......they'll price it lower/lock a price.....cause they KNOW they gonna fill ya a few times during the season.....
Reason i tol'im ta come git they da*n tank..... ......call'd for price on 250 gal b'fore the season Aug, '13.......almost 4.50 a gall then.......was up ta almost 5 bux by T-give'n........
Thats the thing, I can go to my propane place all year and get my 100lb tanks filled for $3 (a gallon) all year. (so far) Last several years. Even in the end of winter when the prices went way up. I don't use them that much or I would have ran a NG line. Just enough to heat the back barn when I am out there.