How are 3rd party flight booking sites so cheap? Whats the catch?

Have a fantastic trip!!

I forgot to mention this, although the site you used might have already done it. If you use a VPN service to change your country of origin on your IP address, you get much cheaper international flights. As part of their pricing strategies, most airlines detect where you’re searching for the ticket from and charge a higher price to travelers from the US.

Similarly, it’s always best to use incognito mode. If you repeatedly search for the same flight they’ll jack the price on you.