Cost: The cost is determined by adding transportation costs, fencing if needed, and sheep as described below. Transportation and fence costs are due upon delivery. Sheep cost is payable when sheep are picked up.
A filling in Australia could cost you anything from $100 - $300. The average according to the ADA (Australian Dental Association) 2012 fee survey (across all states) ranges from $130 for a small silver filling to $283 for a very large white filling.
Keep in mind however, that for your safety and by law, tanks cannot be filled above their 80% capacity. I'm only familiar with prices in our part of the country, but prices range from $12 to $18 to fill a 20# cylinder, which is about 4.7 gallons of gas. Some tank exchange services only put about 18# of LP in the tank. P.S. Tare weight (empty weight) is listed as T.W. on the 20# cylinder and can range from about 16 lbs. to over 19 lbs., so it is smart to pay attention to both the listed empty weight and the full weight after the tank is filled.