Gas prices have gone up 26 cents since last month in the state of Illinois. GasBuddy.com says the statewide average price of a gallon of regular unleaded in Illinois was at 2.43 a gallon, now that price is 2.69 a gallon. The cheapest price of gas found in both Lawrenceville and Bridgeport is 2.43 a gallon. The lowest price of gas in Robinson right now stands at 2.38 a gallon. The lowest price in Olney is 2.39 a gallon; and in Mt. Carmel it’s 2.35 a gallon. The cheapest price of gas throughout the state of Illinois stands right now at 2.23 a gallon.