Avoid Being Ripped Off by the Airlines

March 5, 2008 <br/> Special to ABCNEWS.com&#151; -- You're lusting after that new Mercedes Cabriolet. Or maybe you're in the market for a 10-year-old Camry for your high school senior. And you want a good deal.

You don't pick a price out of thin air; no, you do research, you compare prices, you check in with Edmunds and the Kelley Blue Book.

And guess what? You can do the same thing when you shop for airfare. It's all in knowing how to intelligently compare prices.

When you buy an airline ticket, you're not buying a seat, of course, and you're not quite renting it either. You are purchasing the right to travel from point A to B on a certain day and time. Airline bean-counters track the revenue from your airline ticket purchase by noting the purchase price and then dividing it by the number of miles you have flown: the cents per mile.

The airlines' goal is pretty basic — make sure the cents per mile you pay is greater than the cost per mile it takes to operate the flight. I like to call the airlines' operating cost the invoice price of an airline ticket.

As you might imagine, all kinds of factors go into calculating the invoice price, including the size of the plane, number of crew members, cost of fuel, customer services and more. Typically, the cost per mile for airlines has ranged between 8 and 16 cents. That's right; some airlines operate their planes at almost twice the cost of others — which is how the term low-cost airline was coined.

Take a look at these invoice prices (cost per mile) for a dozen airlines from last year. The data was provided by the airlines to the federal Bureau of Transportation Statistics and is for the third quarter of 2007.