Here in Wisconsin there are laws that are suppose to keep stations from gouging prices. You can only charge so much over the actual cost for gas, you can only raise your prices by this much every day, and you can only raise your prices once a day and so on.
I remember on 9/11 gas stations freaked out and a few got busted for trying to charge $7 a gallon and raising their prices multiple times a day. The laws are their, but not always followed, but we haven't seen a major fluctuation in prices so...