Check the Math on Air Fares

For example, British Airways charges a security fee of $4 per segment, per person, which means you could be charged as much as $16 for a roundtrip flight with one stop both ways. Unlike U.S. carriers, the international carriers have successfully implemented a $10 fuel surcharge per person, per segment, on all international flights. Again, this means you could pay as much as $40 per person for a roundtrip flight with one stop both ways.

Mind you, these are just the fees -- as Barth notes, "airline fees and taxes are even more complex because of all the governments and different levels of government." Local, regional and federal governments add -- or don't add -- certain fees to certain tickets for all manner of reasons. Some taxes are charged to all passengers in the name of airport maintenance, while other taxes are charged more selectively.

The U.S. government charges at least $40 in tax to an international ticket, adding roughly $18 for departing and arriving with a $15 tax for immigration and customs. This is only half the equation, however. If you're flying overseas, the country you land in will charge you as well. The U.K. adds as much as $75 to tickets -- a rate that varies from country to country and fluctuates with the currency exchange rate.

As the chart shows, fees and taxes can add up in a hurry. But with so many moving parts, airlines like Kuwait Air or British Airways aren't being entirely disingenuous when it doesn't add tax to sale fares. It can be too cumbersome to explain in even the finest of fine print.

"It's really easy to cast this as a bait and switch, but it's not evil by design," Berth said. "Depending on the routing, taxes can be different. Like you could end up paying less for a nonstop because you don't stop at some other foreign airport that has to add in fees and taxes, too."

How to Avoid Sticker Shock

The easiest way to avoid sticker shock is to assume that the actual price of an international ticket will usually be $100 higher than the sale fare advertised in the newspaper.

$240 Going on $340 Kuwait Airways has a $240 roundtrip flight between New York and London, but taxes and fees add 40% to the price. Here's a look at how the fees and taxes add up.
Item	Cost
List price of the roundtrip fare	$240
U.S. September 11th security fee	$2.50
U.S. passenger facility charge	$3
U.S. international departure tax	$13.70
U.S. international arrival tax	$13.70
U.K. passenger service charge	$18.51*
U.K. air passengers duty	$35.59*
U.S. customers fee	$5
U.S. immigration fee	$7
U.S.D.A. APHIS fee	$3.10
TOTAL	$342.10
Source: SideStep (* 1 British Pound = $1.78)