Prices are how scarce goods get allocated in markets in accordance with actual conditions. When demand increases, prices go up, all other things being equal. It's not immoral. If orange groves are frozen over (or devastated by Hurricane Charley), leading to fewer oranges going to market, the price of oranges on the market is going to go up as a result of the lower supply. And if demand for a good suddenly lapses or supply of that good suddenly expands, prices will go down. Should lower prices be illegal too?
If we expect customers to be able to get what they need in an emergency, when demand zooms vendors must be allowed and encouraged to increase their prices. Supplies are then more likely to be sustained, and the people who most urgently need a particular good will more likely be able to get it. That is especially important during an emergency. Price gouging saves lives.
Nobody knows the local circumstances and needs of buyers and sellers better than individual buyers and sellers themselves. When allowed to respond to real demand and real supply, prices and profits communicate the information and incentives that people require to meet their needs economically given all the relevant circumstances. There is no substitute for the market. And we should not be surprised that command-and-control intervention in the market cannot duplicate what economic actors accomplish on their own if allowed to act in accordance with their own self-interest and knowledge of their own case.
"Price gouging" is nothing more than charging what the market will bear. If that's immoral, then all market adjustment to changing circumstances is "immoral," and markets per se are immoral. But that is not the case. And I don't think a store owner who makes money by satisfying the urgent needs of his customers is immoral either. It is called making a living. And, in the wake of Hurricane Charley, surviving.