With a cost of living 18 percent below the national average, the small city of Harlingen, Texas, in the Rio Grande Valley had been dubbed the "cheapest place to live in the U.S.," according to data from the Council of Community & Economic Research, which compared prices across 340 urban areas. But before you pack your bags for this "penny pinching paradise," be sure to note Harlingen's high rates of poverty and unemployment. Here, a brief guide, by the numbers:

Average monthly principal and interest payment for a home in Harlingen. "We have relatively low income in the (Rio Grande) Valley, including in Harlingen," says the city's mayor, Chris Boswell. "We have fewer college educated folks." The area also has few high-end retailers.

Average monthly principal and interest payments for a home in Manhattan, the most expensive urban area in the county. Other particularly pricey areas include New York's Brooklyn and Queens, San Francisco, and Honolulu.

Average cost of a loaf of bread in Harlingen

Average cost of a loaf of bread in Manhattan

Average cost of a gallon of gas in Harlingen

Average cost of a gallon of gas in Manhattan

Population in Harlingen

Unemployment rate, in percent, in Harlingen. "There's no work," says unemployed resident Benito Flores.

Poverty rate, in percent, in Harlingen, one of the highest in the nation. The national poverty rate hovers between 13 and 17 percent.

Average annual income in the Brownsville-Harlingen metro area in 2010, per the U.S. Bureau of Labor Statistics

Average annual income throughout the United States. "While Harlingen's cost of living may be 18 percent lower than the U.S. average, area income is about 28 percent lower," says Vanessa Wong at Bloomberg Businessweek.

Sources: Bloomberg Businessweek, Huffington Post, TIME, ValleyCentral.com