Among the top grievances that passengers have against the airlines, pricing tricks of the trade rank near the very top. When an advertised fare ends up costing nearly double the price after all the "extras" are added, something doesn't seem fair. Some European regulators agree.

European Commission vice-president Siim Kallas is considering strengthening airline passenger protections amid a fury of complaints over airline fare add-ons that double the price of a ticket in many cases. Mr. Kallas received a written request for improvements in pricing practices from Brian Simpson, chairman of the EU transport committee. The last straw for passengers seems to have come from a fee added by budget carrier Ryanair to cover the costs of compensation for delays and cancellations. The airline paid out €100m (£88m, US$142m) in compensation over the last year, which included volcanic ash disruptions, work stoppages and winter weather. Given the localized nature of most weather events that lead to delays and cancellations, the €2 (£1.75, US$3) fee appears to be covering more than Ryanair's anticipated compensation costs. It could end up netting the airline €172m (£150m US$242m) this year. This is what has drawn the attention of EU regulators.

Few would argue that an airline has the right to charge what it deems appropriate for its services. What passengers take issue with is the manner in which airlines do this. Laws against deceptive advertising are intended to remove the surprise factor when it comes to buying airline tickets, but consider the following fees – most of which are unavoidable – that could more than double the price of your air fare.

• Paying more for using a debit or credit card (except where prohibited)
• Paying for buying your ticket over the phone or at the airport
• Paying to check a bag
• Paying to check in online
• Paying to check in at the airport
• Paying to choose an exit, aisle or window seat
• Paying to choose a seat with more legroom
• Paying to choose a seat at all
• Paying to secure your fare while you decide

Let's not forget that you also pay government taxes, passenger user fees and the ubiquitous fuel surcharges on top of the increasing number of "extras" airlines are already charging for. Have you considered the fact that you could be paying these before you even step foot on an airplane?

Regulators in the U.S. are also keeping a watchful eye on the way airlines advertise their air fares. The Department of Transportation is pushing airlines to provide the final cost to passengers early in the booking process. As in the EU, there is much support from the passenger community and some pushback from the airline industry which claims that it is giving travelers the options for buying what they value most.

To paraphrase a popular song: it's not what you do it's the way that you do it. OK, maybe it's also what you do after all.