How to find those super-low fares

One of the most useful deal-finding tools on the Internet is Yahoo!'s "Best Fare Tracker." It can quickly determine the lowest possible price for a flight between whichever cities you're interested in watching. This morning, for example, I see that tickets from Chicago to Phoenix are selling for as little as $143, Las Vegas or Washington, D.C. flights are starting at $153, and travel to Boston, Seattle, or San Diego is as low as $163. Those are enticing prices, to be sure. But are they real deals, or are those fares dangling just out of reach, like juicy apples high up in a tree?

What you're really seeing on Yahoo! isn't the price of an actual trip. Rather, it's the cost of a hypothetical ticket on Travelocity, using fares published in that site's system. And because Yahoo! also includes Travelocity's booking fee, as a rule, I subtract $5 from the listed price. That gives me a benchmark for the lowest fare on whichever route I'm watching.

Unfortunately, for multiple reasons, you're never going to be able to find the benchmark price for a ticket on the dates you want to fly. First, the "Best Fare" doesn't include taxes and fees; you'll need to add $20 to $40 to the fare for a domestic trip. Second, the benchmark price is generally only valid for certain dates or days of the week. The fare could be substantially higher for your preferred itinerary. And third, the cheapest tickets could already be sold out. Just because Yahoo! finds a low fare in Travelocity's system doesn't mean that you can actually book at a seat at that price.

But that's no reason to give up your search for a great deal. If you can't be flexible with your travel dates and times, check the price on a few different websites, including Travelocity. Sometimes an airline will offer an exclusive deal that Yahoo!'s tracker won't find. Also, remember that Travelocity doesn't sell tickets on Southwest or JetBlue, so you'll also need to search those sites, either separately or with a scraper like SideStep. Finally, if your trip is at least two weeks away, watch Yahoo! daily to see how the lowest price changes. Airlines file new fares at least three times a day; it's definitely worth repeating your search on Tuesdays and Thursdays, when ticket prices seem to be the most volatile.

If booking a seat at the lowest possible price is your primary goal, the best approach is to adjust your travel plans according to the rules of that particular fare. (You can figure out the restrictions by clicking on "Rules" next to the specific fare on Yahoo!.) The $163 fare to Boston, for example, requires that you complete your trip by February 28, 2005, but you have to avoid traveling on peak holiday dates. And the $163 fare to Seattle only applies to flights on ATA or Frontier. Count on paying more if you prefer a different airline.

But even if you're willing to do whatever it takes to get the lowest fare, you can't guarantee there will be any seats left at that price. How can you tell when there's availability? Travelocity has introduced a new feature that tells you how many seats are left at a given price, but it only appeared for some of the searches I conducted. Usually, I find it's most helpful to rely on the flexible search tools that let you scan a range of dates at once. The best are Orbitz's "FlexSearch" and Southwest's "Shortcut to Low Fares," but you can also find this feature - in one form or another - when you search for tickets on American, Air Canada, America West, British Airways, Continental, and Song. The sites that make the search easiest show you exactly what you'd pay for a ticket on any combination of dates within a certain travel window. And if you know the benchmark price (don't forget to account for taxes and fees!), it's easy to tell which days you should fly on to get the best deal.

So the next time you search for an airline ticket, don't despair if the fare seems too high. Figure out the benchmark price, factor in the taxes and fees, and then be flexible enough with your plans to seal the deal. Or, if your travel dates are set in stone, check a bunch of different sites, wait for the fare to drop (it almost always does), or think creatively, trying alternate airports or a different routing. And that super-low fare you thought was out of reach? It might just turn out to be low-hanging fruit.