Airfare prices often change minute-to-minute or second-to-second. We've all watched a flight that we were interested in booking skyrocket before our eyes (Imagine how Seahawks or Patriots fans felt).

But did you know that your price could go up or down depending on where you book your flight? Yes, location matters- even before you're on vacation. Our travel editor, Mark Jackson, noticed this phenomenon first when he was trying to book domestic flights in Argentina. Pricing was over $500 round-trip for a 2 hour flight, but when he got in-country, fares miraculously dropped to below $250.

The Issue

If you fire up the ITA Matrix, a way to see airfares for city pairs over a monthlong calendar, you can see this practice happen in real life. ITA allows you to not only pick the cities you'd like to travel to, but also the city in which you're booking from. ITA won't allow you to book directly from the website, but we can explore just how to do that a little later.

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You can see here that we've chosen to take a week trip from Buenos Aires, Argentina to El Calafate, Argentina, home to the Perito Moreno Glacier (a UNESCO World Heritage site). At the bottom, you'll see that you can enter "sales city," which is left blank for this first example because we want to see what the price is from my normal booking city, Chicago.

Our search returns the above- $484 for the roundtrip flight. Pretty steep for a domestic flight.

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Now, what if we chose "Buenos Aires" as our sales city instead of Chicago? We get the following results:

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$140 cheaper for booking from Buenos Aires instead of Chicago! For the exact same flights.

How To Book

If you're a planner like me, you don't want to wait until you get to the country to book a flight. Instead, you can choose one of two options to secure your cheaper tickets before you leave.

1. Book from the airline's website in foreign currency

You can first try to book from the airline's website to see if you can save money by booking in the local currency (in this case, Argentine pesos instead of American Dollars). Usually, this works. To do this, look for the airline's dropdown menu asking what country's webpage you'll want. By choosing the local option, you'll see prices listed in the local currency, and after the conversion it should be cheaper than what you're seeing from Kayak or Skyscanner.

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2. Spoof Your Location

This is a little bit more tech-savvy, but not overly difficult to do if you're at least a little bit computer literate. Using a VPN service, you can trick a website into thinking that you're somewhere else. This isn't only good for getting cheap airfares- it also allows you to watch movies on your Netflix account when you're abroad, or access Facebook and Google from countries like China.

More Tips

You'll want a card that doesn't charge foreign transaction fees for this type of travel hacking, since you won't be paying for the flight in the US (virtually, anyway). I like theChase Sapphire card, which is currently offering 40,000 Ultimate Rewards points for meeting minimum spend requirements. You can transfer those points into other travel programs like United and British Airways (award flights are cheaper than paid ones!).