dont know about water coz we are on mains but we usually get a small gas bottle filled at the moment for $25 a 9kg one coz weve been broke but when we do get big bottles we get a 45kg one filled for $100 and that usually lasts about 3 months we did have an option to have 2 but we ran out quicker coz the pressure equalises between the 2 we live in a country town and in town so its not hard to swap it over we used to have an automatic refilling service but they were charging just to come out even if we didnt need any gas we have gas stove and hot water