Post Katrina gas prices maybe went up 10-15% depending on where you lived and in most cases they have rolled back down. Nevertheless, cries of price gouging were rampant and continue. But that is gas. If it is some other good like, say, oysters then it is a feel good story:

With two-thirds of Louisiana oyster beds wiped out by the Aug. 29 storm, prices of Pacific oysters have soared as Gulf Coast processors scour for alternatives thousands of miles away. That’s allowed Taylor Shellfish to raise its prices 38 percent in the past month to $40 per gallon of oysters.
“It’s the strongest demand that I’ve ever seen for oysters,” says William Taylor, ……
Prices have surged as much as 50 percent since the hurricane, according to the Pacific Coast Shellfish Growers Association, giving the Northwest growers some relief, even as they sympathize with the hurricane victims 2,000 miles away.

Imagine the outcry if gasoline prices had gone up 50%!
Seems like so-called market forces working the way they should in both cases. It can, though, be a bit hard to tell if the market is really working in the extensively regulated and subsidized oil and gasoline business.