Okay, you just provoked me into logging on to "Gas Buddy". They show Costco prices at $2.45. We dropped our Costco membership years ago when the closest one to us became a "business center." Sam's Club is showing up at $2.49 to $2.75. Except at the one close to us. Then there are a few at 10 to 15 cents less than $2.99, but they are all far enough of that I'm not going to spend the time (traffic!) and miles to get to them. Especially with an 11 gallon tank. I put 7 gallons in it yesterday. Driving across town to save a buck or less ain't gonna happen.
Gas Buddy shows the highest prices (regular) running from $3.21 at a 7-11 to a Sinclair at $3.39.
In or near MY turf, $2.99 is the best I'm gonna get at the moment. I would find it hard to believe that we pay more because we're in a higher income area. Our household is pretty average.
ETA: From an article in the Las Vegas Review Journal in March
After Southern Nevada’s four-month honeymoon with reduced gasoline prices, motorists now have been hit with the perfect storm.
Refinery maintenance. Preparations to manufacture “summer blend” fuel. A refinery workers strike. Gasoline supply speculation. An explosion and fire at yet another refinery.
http://www.reviewjournal.com/business/energy/here-s-why-southern-nevada-gasoline-prices-skyrocketed-again