Get There for Less Booked your summer vacation yet? Here's how to find the best price for your flight.
By Nick Pachetti

(MONEY Magazine) – It seems everywhere you turn, someone's getting a deal on an airline ticket. An auctioned fare. A last-minute fare. A dirt-cheap fare. For any particular flight, there are a multitude of ticket prices and a host of companies that will sell you a seat. And chances are you can find every one of those ticket prices on the Internet. The proliferation of travel sites can be an invaluable tool for travelers looking for low fares--but it can also make the search seem more daunting and confusing than ever.

If you don't think you need help, consider how online options are expanding. Airlines are luring fliers to their websites with online-booking incentives and Net-only fares. The major travel sites keep improving to stay ahead of the growing competition. And this summer, the major carriers will launch their own online-reservations supersite, dubbed T2, which they hope will become passengers' one-stop shop for discounted fares.

So, as the summer travel season kicks into high gear, we've come up with the best strategy for booking a flight, including where to start and where to go next if you have more time to search and flexibility about when you can travel. Our system mirrors the way airlines price tickets, starting with the discounts that give you the most choice.

Finally, this strategy assumes you're booking a fare in advance, not relying on the risky method of waiting for a last-minute fire sale. If you find yourself itching to get away for a summer weekend on, say, the Tuesday of that week, our favorite sites for last-minute deals are www.bestfares.com and www.smarterliving.com, two sites that track airline discounts.

ESTABLISH YOUR BASELINE

Your starting point should be the airlines' starting point: the so-called published fare. On every flight, the airline divides the economy section into fare classes, whose prices vary based on such restrictions as how early you book, what days you travel and how long you stay. (The letter you'll see on your ticket corresponds to these classes.) Of course, airlines continually change prices and restrictions to fill their planes.

As soon as you know where and when you want to fly, the easiest way to look up the published fare is to go to Expedia (www.expedia.com) and Travelocity (www.travelocity.com), the two travel sites that account for almost half of online bookings, according to Web-research firm PhoCusWright. At both, you have direct access to computer databases known as central reservation systems (CRS), which in turn access a single computer that stores fare information for all flights and the individual airline systems that track availability.

Why bother with two sites? While we find both easy to use and reliable, we've noticed something else: Expedia and Travelocity don't always come up with the same fare for the same flight. Recently, Travelocity found us a $226 round-trip flight from Chicago to San Francisco in June; the best Expedia came up with was $634. (For the record, Expedia crushed Travelocity on another trip.)

Chalk up the disparity to technology. Each website has its own search software and accesses different CRSs. Travelocity uses Sabre, the biggest CRS; Expedia uses Worldspan but has just started tapping the central airline fare database as well, which could give Expedia an edge.

Once you get a quote from each, write down the numbers and keep looking. "If there's anything that's going to happen to that starting price, it's going to go down," says Tom Parsons, editor of Bestfares.com.

FINESSE THE SYSTEM

Seasoned travelers know that the way to find a better fare is to be flexible, and what both Expedia and Travelocity have going for them--in addition to access to published fares--are tools that let you see how a few changes can lower your fare.

At Expedia, for example, you can search by "specific travel dates" or "flexible travel dates," and a link lets you experiment with date changes once your fares are displayed. Travelocity allows you to define your search based on your willingness to change days, change flight times or not change at all. At both sites, if you can be flexible about the days you travel, you can enter the cities you're traveling between to get a list of best fares, the airlines offering them and the dates they are available (displayed on color-coded calendars). In April, Expedia introduced a "Build Your Own Trip Flight by Flight" search option, which lets you fine-tune flight times on a single screen.

Travelocity, on the other hand, makes it easier to check out flights into and out of alternative airports--where fares may be lower. The "search for the closest airport" link gives you airport names, codes and miles from your first choice. By plugging in the airport codes on your original search page, you can see if your price changes.

OFFLINE OPTION. If you don't have Internet access--or the hour or so it could take to search for a fare online--have a travel agent do it for you. Because airlines have cut travel agent commissions, you may pay $10 or so a ticket.

SEE WHAT YOU MISSED

In an effort to get customers to book directly over the Internet, airlines have, in effect, created a new ticket category: special deals that are available only at the carrier's website. For example, the Southwest Airlines site recently offered a $48 one-way fare between Los Angeles and Salt Lake City, good until September. The best published fare for the same route that Travelocity offered was $150 round trip. (Airlines are also rewarding travelers who book online with bonus frequent-flier miles. United, for example, was recently offering 3,500 miles for booking at their site.) So once you've got the best price from Expedia and Travelocity, visit the airline sites, especially if you're accumulating frequent-flier miles or know that the carrier dominates a particular route.

There are also shortcuts. Airlines often mix news of these specials in with the last-minute fare sale notices they e-mail every week. To subscribe--which in some cases involves joining the frequent-flier program--go to the carriers' sites, which are listed in the table at right. Also check Bestfares.com, which regularly posts the latest airline specials, and Trip.com (www.trip.com), where you'll find IntelliTrip, a travel bot that scans the websites of 16 different airlines, including American, Delta and United.

PROFIT BY COMPROMISING

If you're determined to beat the published fare, you have another option: unpublished fares that are available only through consolidators. These wholesalers, some of which are owned by the airlines, obtain discounted tickets from carriers. You can save anywhere from 25% to 45% off published fares--if you're willing to make some compromises: Consolidator tickets are typically nonrefundable, nonchangeable and, on some occasions, not eligible for frequent-flier miles.

Just as the Internet has brought travel-agent booking systems directly to consumers, the Web is making consolidators easy to find. The major ones online are Cheap Tickets (www.cheaptickets.com), Lowestfare.com (www.lowestfare.com) and 1travel.com (www.1travel.com). Recently, when round-trip flights from New York City to Sacramento were hovering around $750, Cheap Tickets offered one for $290.

OFFLINE OPTION. Another way to find a consolidator who's selling tickets on a route you're interested in is to check ads in your paper's travel section. Heavy travelers might pick up the Index to Air Travel Consolidators ($56; 800-241-9299), a guide to more than 200 consolidators.

TRY YOUR LUCK AT AN AUCTION

You know what comes next: Name your price on the Net, and see if the site will meet it. We've always been dubious of Priceline (www.priceline.com), the site that created and continues to popularize this auction system, because the site forces you to accept a nonrefundable flight before you find out what time it leaves and how many layovers it subjects you to.

If you can accept that lack of control, we will concede that Priceline can work, as long as you're savvy about how you bid. Here's our method: First, keep in mind that the maximum discount that you have a good chance of getting is 30% off the lowest published fare. So if you can't find a consolidator ticket that's 30% off, bid that amount. If you go for a deeper discount, you'll likely be denied. You might win the auction with a higher bid, but we think a small savings doesn't make up for Priceline's uncertainty.

There's one more reason we're softening on Priceline. Now the site guarantees a flight within a ridiculously large window, between 6 a.m. and 10 p.m. But this summer Priceline may start offering deals where you can specify a four-hour window as long as you stay a full weekend. That would be a big improvement over more random booking.