(Reuters) 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 flight changes; fees for your bags. Fees, fees and more fees. "A lot of travelers are realizing they can't just price-shop anymore," says 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 versus the competition, but travel experts suggest comparison is still possible. "You have to do the math," says Seth Kaplan, publisher of the industry publication Airline Weekly. "You really have to really think it all through." 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.

What's Going On 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. So when you are going to fly, it's important to figure out what you would be willing to pay extra to obtain. "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 founder of BeFrugal.com. Consider charges for such things as early check-in, extra leg room, checked bags, and snacks "to calculate the true cost of your flight. Be honest about your needs. If paying for extra leg room will improve your trip, it may be worth the extra money." Travel Graphic