The Florida cities are fairly easy to explain: Orlando is a huge tourism center, with good competition from multiple airlines. Ft. Lauderdale not only has airline competition but competition from another big airport -- Miami International -- just 27 miles away.
However, Atlantic City is harder to explain, but I'll try because under most circumstances, I would not put it on any list of cheapest airports. The BTS does, though, and this is primarily because of the relatively small number of total flights mostly between Florida on the ultra-low cost carrier Spirit. Comparing Atlantic City to Dulles Airport in Washington D.C. (the fourth most expensive according to BTS) is like comparing apples and mangos.
But if you live in South Jersey and want non-stops elsewhere or just cheaper fares in general, drive an hour to Philadelphia. A flight from Atlantic City to Las Vegas this month for example, will cost $383 roundtrip, and that includes two stops. Fly from Philadelphia and it costs just $219 with one stop or $237 non-stop. Is it worth it to you drive for an hour to save from $146 to $164? It would be to me, especially with a few in the group.
Which brings me to my advice for those who live near expensive airports. Look at a map, find the big hubs near you and compare prices. And be prepared to drive if it's worth it.
Say you live in Huntsville: you may find fares to Cincinnati are substantially cheaper out of Birmingham, and that fares to Chicago are cheaper out of Nashville.
Live in Grand Rapids? See what's doing in Detroit or Chicago. Call Savannah home? Check out the prices in Charleston, S.C. or Jacksonville, Fla.
One last thing: a significant portion of the total price of your ticket includes government taxes and airport fees (typically over $50 for a domestic connecting roundtrip). Additionally, airlines pay airports landing fees which vary from airport to airport that can make your airport more or less expensive.
Southwest CEO Gary Kelly is on record as being perplexed by "expensive" airport landing fees, especially those that go toward creating what he calls "monuments" instead of functional airports. Who pays these fees? You do, ultimately.
Speaking of Southwest, you might want to check out that carrier's home airport, Dallas' Love Field. It's in the top five of that list of cheapest airports.
This work is the opinion of the columnist and does not reflect the opinion of ABC News.
Rick Seaney is one of the country's leading experts on airfare, giving interviews and analysis to news organizations, including ABC News, The New York Times, The Wall Street Journal, Reuters, The Associated Press and Bloomberg. His Web site FareCompare.com offers consumers free, new-generation software, combined with expert insider tips to find the best airline ticket deal.