If you bought a home 10 years ago for $100,000 and just sold it for $300,000, have you engaged in price gouging? Most people would say "no," provided there were willing buyers and sellers of both sides of the transaction merely responding to the market at the time.
As a result of hurricanes Katrina and Rita, some politicians have demanded prosecution of "price gougers." In many states, like Florida, "price gouging" is illegal. The Florida statutes say, "It is illegal to charge unconscionable prices for goods or services following a declared state of emergency."