Trying to find the best deal for a flight used to be a lot easier. All you had to do was look at the price of airfare, and you could easily compare one to the next.
Not anymore. As the summer travel season ramps up, it's all about the fees: fees for boarding passes; fees for seating; fees to make flight changes; fees for your bags.
"A lot of travelers are realizing they can't just price-shop anymore," said Annie Wang, senior travel strategy analyst for the website TravelNerd.com.
It's certainly more involved for consumers to weigh the cost of traveling with a particular airline compared with the competition, but travel experts suggest it is still possible.
"You have to do the math," said Seth Kaplan, publisher of the industry publication Airline Weekly.
Homework is necessary because the picture changes constantly. Earlier this month, Frontier Airlines became the third carrier to charge certain passengers for carry-on bags. Most of the leading U.S. air carriers recently announced increases to the cost of changing flight reservations. And it is no longer a given that you can sit with a family member -- you may have to pay extra.
Indeed, some airlines apply a seat surcharge that varies if you sit in a window, aisle or middle seat. In 2012 alone, airlines changed 52 fees, raising 36 and mostly mixing others together, according to a TravelNerd survey.
The growth of what is known in the industry as "unbundling" -- essentially making your ticket more of an a la carte affair -- has been a big plus for the airline industry. Airlines in 2012 collected more than $6 billion in baggage and flight change fees alone, according to U.S. Department of Transportation data.
Unbundled fares are more in line with how consumers make the rest of their purchases, said Robert Mann, an airline analyst for R.W. Mann & Co. Inc. You pay for as much, or as little, as you require.
As airlines test the limits of how much consumers are willing to pay, several have also begun bundling add-ons to the base fares in packages.
U.S. carriers, including American Airlines, are following a path already charted by Air Canada, which has created tiers with various bundles of services packaged into a single add-on charge.
To help consumers sort through the fees, several travel sites -- including Kayak.com, TravelNerd.com and SmarterTravel.com -- feature comprehensive lists. Seeing what you could be getting charged for can help provide a sense of how much you can expect to add to the base airfare.
"When looking on a comparison site such as Orbitz, add in the additional fees based on what you'll need," says Jon Lal, a frequent traveler and BeFrugal.com founder.
Southwest Airlines and JetBlue Airways have bucked much of the fee trend, for travelers who have the option to use those airlines. Neither charges for the first checked bag. Southwest does not charge for a second or charge a fee for changing a ticket. Most airlines charge $200.