Gas prices in Arizona are starting to inch down on average. Triple-A Arizona says the average price of gas in the state is down a half-cent to $2.90 a gallon. In Flagstaff, gas is also down a half-cent on average from last week to $3.00 a gallon. However some stations are selling gas for $2.75 and lower. In Prescott, prices are nearly unchanged, staying at $3.01 a gallon. However, some stations are selling gas for $2.85 and lower. Officials say expect some slight fluctuations in prices at the pump through the end of the month due to lower supply and refinery maintenance.