Experts sound off on whether those low fares are worth grabbing.

Despite the fact that we’re all staying home right now, it’s hard to deny the allure of really good, cheap flight deals. And with the entire airline industry in free fall these days, there are some once-in-a-lifetime deals to be had—we’re talking $13 cross-country airfares, and $200 roundtrip flights from the U.S. to Europe. But should you book them right now? Before you mad dash to Google Flights and pull out your credit card, experts say there are a few things you keep in mind before jumping on any of those cheap flights. Below are a few airline whizzes to weigh in, so you know what to do the next time you spy an irresistible fare.

Be realistic about the dates

Though there is a ton of uncertainty over when we can travel again, everyone agrees there’s no sense in booking a trip you know for certain you won’t be able to take. “We’re seeing historically cheap flights, unlike we’ve seen in the last 10 years,” says Jesse Neugarten of Dollar Flight Club. “But we don’t recommend anyone booking flights or traveling within the next month or two. If you’re booking travel it should be for June or after.”

Scott Keyes, of Scott’s Cheap Flights, suggests going slightly more conservative—and promises you won’t be missing out on these deals by doing so. “The only flight deals we’re sending [to Scott’s Cheap Flights subscribers] are at least three months in the future: July, August, and further out,” says Keyes. “But it’s not only fares in the next month or two [that are cheap], but also those well into the fall and winter.” Deal continue for months out, including over peak seasons, like summer, Thanksgiving, Christmas, and New Year’s, they say.

Always read the cancellation policy

Before you jump on that cheap winter flight deal? Make sure you consider the possibility, no matter the date, that you may have to cancel—and you want to be in the position of power if and when you do.

“I would only book a flight right now with an airline that is waiving the normal change fees,” says Keyes, noting that, typically, such fees will run you a couple hundred dollars. “If you book a flight for August and it’s still not safe, you don’t want to be paying to change.”

Many airlines have introduced generous cancellation and rebooking policies to accommodate customers, but policies vary by airline—so make sure you read the fine print before assuming you can change your plans with no penalty. Currently, Delta Air Lines, whom Neugarten says tends to be the most generous towards passengers, has waived change fees for the next two years, through May 31, 2022. Other airlines have more limited, but still unprecedented, offers. American Airlines, for example, is waiving fees on all flights booked now through May 31 on trips that will take place by the end of the year.

Know a good fare from a great one

Gary Leff, the author of and an expert in points and miles, says to keep one filter on at all times. “It all depends on how amazing a deal you’re getting.” Even if you know you can change your flight with no financial penalty, it still takes time and energy to book and cancel. So, make sure to focus your bargain hunting on the real steals.

The experts we spoke to noted that quite a bit goes into the art of spotting a deal, from understanding usual prices, and variables like time of day and time of year (after all, sites like Dollar Flight Club and Scott’s Cheap Flights have made an entire business out of it). But, there are a few ways for a layman to employ a critical eye.

“We have a few benchmarks we use,” says Neugarten. “For Europe, if you see anything under $300 round trip on a main carrier, especially for summer or peak, you should book that. For Asia, anything under $350 is a ticket to book, and for South America, anything under $400. We’re also seeing deals to South Africa under $450, which is a price you’re only seeing because of what’s happening right now.”

As you scan those deals, you’re likely to see prices that reflect the drop in demand—but you’re also likely to spot mistake fares. “Mistake fares are typically pretty rare because, by nature, they’re a mistake,” says Keyes. “But because the airlines have been doing such major surgery to their schedules, the conditions are right for mistakes to happen.” Though occasionally an airline won’t honor mistake fares, Keyes say 85-90 percent of the time they do, and he expects airlines to do so now more than ever simply because they can’t afford the bad marketing of canceling on people. And that’s great news, because Keyes reports seeing unheard-of mistake fares lately—including a $23 flight from Boston to San Juan over Christmas and New Year’s Eve. “If you don’t take advantage of a deal like that, in a few hours it’s almost certain to be gone. And you’re not going to see that again.”

Expect these deals to continue for some time

The odd mistake fare may be fleeting, but, overall, these experts agree these great prices will be around for a while. “As flying comes back, it won’t be like flipping a switch and the planes are full,” says Leff. “So I wouldn’t feel a need to jump on a good not great price today, because there will be good, possibly great, fares later.”

Neugarten, whose team recently compared current flight prices to those post-September 11 and the 2008 recession, says we should expect these deals to continue into 2021 and possibly beyond. “We’re seeing that prices over the next year will be 35 percent cheaper than before the coronavirus pandemic,” says Neugarten. “Even though airlines have cut 90 percent of routes, there are still way more seats available than people who want to take those flights, which is why these prices are dropping so significantly. Over the next few years, as demand rebounds, were going to see that equation flip flop: Demand will be higher than the number of seats, and airlines will be slow to add routes back, so prices will likely start to increase.” As things stand now, Neugarten gives it three years until that flip happens.

Judging by prices before the pandemic, Keyes is also optimistic. “A lot of people have noticed that fares have been really cheap since coronavirus popped up, but what they’ve missed is that fares have been cheap for years,” says Keyes. “We’ve been living in the golden age of flights. It has never been this cheap to travel internationally, and that was true six months ago.”

If all this deal talk has you ready to book, here’s the low-down on finding cheap flights. You can let the deals come to you, via newsletters like Dollar Flight Club and Scott’s Cheap Flights, or use Google Flights to search yourself like they do. “Using their calendar view, you can search for different destinations and see all of the deals currently available,” says Neugarten. “That’s one of the ways we do it.”

As you scan those prices, Keyes says the ultimate deciding factor is a personal one: “I wouldn’t book flights now that you’re not really excited about, or fares you’re not really excited about,” says Keyes. “So the question is: Would you regret it more if you don’t book that flight and the deal disappears, or if you book it now and later decide you don’t really want to go?”