$2.30 for gas: Cheap summer blend like 'last-season clothes at Nordstrom'

I've noticed that the price difference between Costco gas and regular gas stations has widened significantly over the past few months.  Costco used to be 10-20 cents cheaper but now it's more like 40-50 cents cheaper than the next cheapest alternative.


$2.30 for gas: Cheap summer blend like 'last-season clothes at Nordstrom'
http://www.ocregister.com/articles/price-723924-gas-gallon.html