Question: how much does it cost to run a gas log fire?
Answer: In Natural Gas, there is 100,000 BTU in a Therm. In Propane, there is about 91,500 BTU in a gallon. So based on those numbers, in order to operate a 70,000 BTU/hour decorative gas log set it would cost you roughly around $0.70/hour for natural gas and about $2.30/hour for propane.