"The short answer is every extra is worth it," said Bruce Margolis, the director of global operations for a consulting firm who lives in Orlando and is a frequent traveler. "After all, you get some value from it. However, not every extra is worth it to everyone.''
When taking a flight, possible fees range from services that were once included in the basic fare — like a meal — to access to an airline lounge which was once reserved for those with memberships but may now be open to any passenger willing to plunk down cash for a day pass.
All those extras have been a boon to the airline industry. From April through June, the most recent period available, U.S. carriers reaped $931 million in luggage fees and $661 million from charges for changing reservations, according to preliminary data from the U.S. Department of Transportation's Bureau of Transportation Statistics.
Fliers who've earned elite status with airline loyalty programs can often get upgrades to premium seats and other perks at no extra cost. But those who need to pay should do their homework to determine what's worth the extra bucks. (Read more: Add-On Airline Fees: Good or Bad?)
"You need to think through what's important," said Jami Counter of SeatGuru.com, a site that tells travelers about airline cabin features. "If you want to get through security quickly. If you want to get off the plane quickly when you land. You want to look at different options."
There's much more to picking a seat nowadays than choosing a window or an aisle, or coach versus first class. Airlines have carved out premium sections that offer a few extra inches of leg room and may allow passengers to be among the first off the plane by sitting closer to the front.
Counter has particular praise for Delta's "economy comfort" section, United's "economy plus" and JetBlue's "even more space." "Three or four inches of additional leg room are a big thing for most people, especially on a long- haul international flight," says Counter. He added that some packages pair premium seats with other appealing perks, like JetBlue's, which offers early boarding and a quicker pass through security at some airports.
A roomier seat means a lot to Larry Seal, the CEO of an executive coaching firm who lives in Beverly Hills. "I am 6'3," he said, "and I would and do pay a mint for it." (Read more: Legroom Crunch: More Airlines Reduce Space, Add Rows)
Bob Milk, a management consultant from Queen Creek, Ariz., said when you have connections to make, paying to be the first one out of coach is a good idea.
"On all legs but the final leg, I will pay for the privilege of sitting in the front of the coach cabin," Milk said. "This has been critical when there are flight delays impacting the arrival time of the earlier legs."
Some see their flight as a chance to unplug and unwind. But for those who need to get work done, frequent fliers say in-flight Wi-Fi is a good buy.
"That is my must-have and is worth every dime," says Don Yaeger, a leadership speaker and author who lives in Tallahassee, Fla.
Still, George Geary, a traveling culinary professional who lives in Corona, Ca., says that he will only pay for in-flight internet access some times, such as when he's sitting towards the front of the plane. Otherwise, he says, it's a waste of money since the seats are so close together, he can barely make out his computer screen.
The Global Entry program, U.S. Customs and Border program which has a $100 fee, is also good value, many international travelers say. It allows them to skip immigration clearance lines when they return to the U.S. and checkin at a kiosk instead.
It's worth it "even if you're only doing a couple of international trips a year," said Tony Goddard, an executive vice president of a manufacturing company who lives just outside Syracuse, NY and flies regularly to Asia, as well as Europe and Brazil. "(It's) $100 for 10 years and cuts your wait from upwards of 2 hours sometimes to just 2 minutes."
Avi Rosenthal says when it comes to Global Entry, premium seats, and in-flight WiFi, he'll take all three.
"Anything that I can do to ease the burden, get better connected or make the trip more enjoyable is worth it," says Rosenthal, a vice president at a home security firm, who lives in Harrisburg, Pa. and travels nearly five days a week.
Lesley Trudelle, of American Express Travel recommends travel insurance. "It can occasionally seem like an unnecessary expense," she said, "but, when you do need it, you are so glad to have it." And she and other travel experts and frequent fliers say an airline-lounge pass can also be good investment, especially if you have a long wait or need to get work done.
It's not just the airlines who charge for certain perks. Susan Jacobsen, president of an executive recruiting and media consultancy firm, who's based in Washington D.C., said she'll pay extra for club-level access at some hotels "for added comfort and convenience," she says.
But it you jotted down most of the airline services worth paying for, Jennifer Dennis would check none of the above.
"None are worth nickel-and-diming under general circumstances," said Dennis, a project manager consultant who lives in Pittsford, N.Y. "Stick with an airline that meets most of your needs . . . A lot of the extras then come for free as part of their loyalty program."