The next time you're on an airplane, think about how much money you spent on your ticket — and then imagine how much the person next to you paid.
The prices might be wildly different. That's because plane ticket prices are "uniquely volatile," according to Scott Keyes, founder and CEO of Scott's Cheap Flights, a Portland, Ore.-based newsletter that sends daily airfare deals to 2 million-plus subscribers. Finding good prices, he says, has become an art form in and of itself.
"Airfare is unlike anything else we buy," Keyes tells CNBC Make It. "It is uniquely priced. It doesn't behave like other things, and as a result we face uncertainty [when buying]."
You may buy a round-trip flight for $500, only to see the same seats going for $250 the next day. Or, you hold off on buying that $500 flight because you hope the price goes down, and end up watching it climb up to $750.
"Nobody sets out to book expensive flights," Keyes says. "We wind up booking expensive flights."
The reason, Keyes says: Often, people avoid making purchases against their better judgment, or allow irrational thoughts to get the better of them. Here, he breaks down a few psychological and mental biases that prey on consumers looking for airfare:
One of the worst things you can do while searching for airfare: waiting until the last minute to purchase your seats, hoping that prices will drop. This, along with tactics like clearing your cookies or searching in a private browser tab, is what Keyes calls "wishful thinking."
"Waiting until the last minute, in the hopes there will be a sale, is not going to do anything to get flights cheaper," Keyes says. "It bears no real relationship to the reality that flights are almost certainly going to get more expensive in that time, and as a result, you might end up overpaying."
He says that while you can realistically hope fares will get cheaper when you give yourself plenty of time to find a flight, you shouldn't hold onto that hope once your departure date is looming.
"The bygone era of cheap last minute standby flights has not existed for a long time," he says. "[Waiting] is a recipe for disaster. You want to make sure your strategy is grounded in actual best practices."
Searching for airfare can be anxiety inducing, and the urge to put off the process can be tempting. Keyes recommends searching during what he calls the "Goldilocks window," which he suggests is the period during which the best rates on flights tend to be found. It isn't too long before the travel date, nor is it too close, he says.
For domestic flights, Keyes says the Goldilocks window is usually between one and three months ahead of your travel dates. For international flights, it's between two and eight months ahead of time.
"Most airlines start selling their flights 12 months ahead of travel," Keyes says. "But if you book your flights a year in advance, the prices on those are generally not good."
Many travelers base their purchasing decisions on the price they paid for their last trip. At the risk of sounding obvious, Keyes says, you should instead focus on what the best prices actually are.
Say, for example, that you flew round trip to Paris in 2011 for $1,000. Now, you want to return — and you're seeing comparable flights that cost a very similar $1,100.
"You might say, 'OK, that's about what I paid last time, that's a pretty good price,' without realizing that cheap flights are popping up all the time," Keyes says, adding that with time and patience, you should be able to find a round-trip flight from anywhere in the U.S. to Paris for under $600 right now.
Similarly, you might see a particular airfare hover at the same price for several weeks — and assume it's the lowest it'll go. This, Keyes says, is a mistake: "Airfare can stay at once place for a long time and [then] drop out of nowhere."
Often, Keyes says, people are willing to purchase an expensive flight if they're scared the price will increase even more. There's a psychological reason for this: According to research from Nobel Prize-nominated economist Richard Thaler, people derive twice the amount of negative emotion from losses as they do positive emotion from gains.
In the context of airfare, Keyes says, that means travelers can miss out on better deals if they feel they're at least avoiding price hikes. "Let's say you're looking at a flight to Paris that's $1,500. That's a terrible price, but you might book that flight because you're worried it'll go up," he explains.
In other words: Don't rely on your most recent trip as a frame of reference. Consider if you're safely within the Goldilocks window, and allow yourself to wait for a better price.