European budget carriers promise big savings. Nick Trend makes sure they deliver

After a decade of genuine fare-cutting, European no-frills airlines have started to raise their prices. But you wouldn't know it from their advertisements. Most are trying to mask the increases by quoting low and then charging extra for services that are traditionally included. In some cases, you could end up paying double or even triple the price that first catches your eye.

For instance, I tried booking a round-trip fare from London to Rome on Ryanair, the biggest of the budget airlines. "One million seats for £5 [$7.35] each way," hyped the banner on the Web site. Then came my first disappointment: The offer was only for flights before the end of January; I wanted to travel in March.

When I chose the dates and times I was looking for, the fares still looked reasonable at $30 each way. Until, that is, I noticed the tinted box alongside, which showed the fare with compulsory government taxes and airport and airline fees added. These doubled the round-trip cost to $123. On the next page, I was informed that checking a single bag would add another $35 round-trip. Since there is no assigned seating on Ryanair, you may also want to pay $9 to be among the first few dozen passengers to board. The total had now soared to $167. Then, unless you have something called a Visa "Electron" card (not many people do), you have to add $6 per person per flight segment to use a credit card.

Final total: $179. So much for the $7 bargain.

Ryanair is not the only budget carrier to slap on extra fees. EasyJet, Bmibaby, Flybe, and others all charge for checked luggage, for example. But there are things you can do to keep fares down:

· Carry on bags. Most no-frills airlines allow hand luggage weighing up to ten kilograms (about 22 pounds).
· Check in early. Be among the first at the gate so you don't have to pay for priority boarding.
· Compare fares on full-service carriers. On the same dates and for similar times as the Ryanair fare, British Airways was offering round-trip flights to Rome for $156—including checked bags, assigned seats, and in-flight food and drinks.
· Don't carry sports equipment. A bag of golf clubs costs $74 round-trip on Ryanair but is free on British Airways.
· Book well in advance. Fares normally rise as the departure date approaches.