We once swore we’d never fly basic economy again, but we’ve since changed our minds. Here’s what we learned over the past few years of flying on budget deals.

If you’re looking for flight deals either domestically or abroad, you’ll probably see a ton of fares low enough to make your jaw drop. But the truth is that once you add a checked bag and a seat selection, you could be paying $200 extra—or even more—and the flight paths or times may be really inconvenient.

Most airlines have started offering no-frills “basic economy” fares, which essentially get you a seat on the plane and nothing else—maybe a Diet Coke on the rocks 😉

If you’re on a time and money budget, you’ll want to look closely at cost vs. convenience. Here are three tips for navigating these fares.

1. Read the Fine Print

What’s included in these basic rates will vary from airline to airline, so you’ll want to read the fine print very carefully before purchasing to make sure it suits your needs. Most of the time you will have a randomly assigned seat at the back of the plane (that can’t be upgraded or changed), and you will board in the last group. You may or may not have access to overhead bins and will have to pay (possibly $120) to check a bag. Also, you are not guaranteed a seat next to your travel companions, so if you are flying with kids, this might not be a wise option.

2. Know what you can’t live without

Everyone has those creature comforts they need to make air travel bearable (maybe even enjoyable 😱). Perhaps you must check a bag. Maybe you really like the option for cheap, last minute upgrades to business class. We never check bags, but we do need overhead space. And for us, being able to select our seats in advance is really important. We learned the hard way, the first time we flew basic economy, that on Delta we could not select our seats in advance or even pay extra at the airport for a better seat that went empty while we sat in the back by the bathrooms. (We’ve never opted for basic economy on American, because they don’t let you select your seat in advance either).

By comparison, United allowed us to use overhead space and select seats in advance for only $25 each on a direct flight from Washington, D.C. to Amsterdam. The seats were still in the back, but especially since the plane was new and a 2-3-2 configuration, this was all we needed for comfort. We wound up paying only $650 for a wonderfully pleasant direct flight to Europe on United that included meals, snacks, beer and wine, and extremely attentive service. (Delta’s website says you have to purchase Comfort Plus to get attentive service—but in reality we had great flight attendants on our last trip to the Caribbean).

3. Price Out the Options

Sometimes you’re better off purchasing a regular economy fare and sometimes it’s worth it to get the basic economy tickets. First, figure out the difference between the two fares and what comes with them. So, for example, if the standard economy round-trip fare costs $100 more and includes a checked bag, but the basic fare charges $120 for a checked bag—and you plan to check a bag—you’ll obviously want to go with the standard fare. Note, however, that the checked-bag price is sometimes the same for both fare categories. You just have to look. Since we only needed an advance seat selection on our United flight, it was worth it to get the basic fare and just pay the $25 extra (per seat per flight).

Next, figure out what comforts you will go without in basic economy and whether you can live with it (this might depend on the length of the flight and size or configuration of the plane). Do you need preferred boarding, extra legroom or free booze? If so, you’ll want to upgrade to the comfort/extra-space economy seats and you generally can’t do that with a basic economy ticket. The biggest thing is to know what you’re purchasing before you click “buy” and to recognize that every airline—and sometimes different routes on the same airline—have different rules.

Our experience with Iberia was HORRIBLE. They use a third-party budget carrier called LEVEL, don’t really advertise it clearly, and let LEVEL treat you like cattle and shirk responsibly. Boarding was a zoo, they didn’t even give free water to basic-fare passengers and the landing was a nightmare!

But can you tell we had a great experience with United’s U.S. to Europe basic economy flight? We were really impressed. We saved $600 for two tickets by flying basic economy to Amsterdam and then hopping an EasyJet flight to Croatia (our intended destination).

Bonus tip: We also highly recommend using EasyJet to fly around Europe. It’s nicer than Ryan Air (it’s like the Southwest Airlines of Europe). Book directly on their website, and you can add extras for cheap (like priority boarding and seating).

We hope this helps!