If you're along the Gulf coast, you should definitely fill up first thing in the morning. It doesn't matter what the cost is. Chances are power will be out for several days over the next week on the coastal areas. Has nothing to do with cost; it has to do with supply! When power goes out, you will not be able to gas up. If visitors/evacuees are in your town/area/city, supply will be limited. Fill up at every chance you get. If you have an extra vehicle at home, fill it up too and put a stabilizer in it to preserve it for a few months, if need be.
Will the price be up? Probably. But you're talking about a difference of $1.50-$5.00 a tankful, based on the increase in price, unless the governor in the state has warned against price gouging. Just keep your tank FULL every chance you get. Supplies may be limited in the next week or so. DON'T STALL BECAUSE OF AN INCREASE OF $10 A FILLUP! Just get what you need and forget it.
Protest to the governor later, and save your receipts, but get your gasoline.
Noodle