oil and gas prices THe average gasoline price per gallon (in cities) and the cost of a barrel of oil shown below for a random selection of weeks in 2015. oil: 87.80, 47.67, 58.03, 53.18, 40.38, 41.06. Gasoline: 3.050, 2.680, 3.044, 2.627, 2.443, 2.349​