Yes. Airlines use 'dynamic pricing' based on point of sale. You are simply choosing the point of sale that benefits you most.

Why does the price change?

Airlines adjust their base fares to match the purchasing power and competitive landscape of specific markets. When you browse from a different region, you trigger those local market prices.

Will my credit card be declined?

Occasionally, a bank's fraud detection will block a purchase made in a foreign currency if it's unusual for your spending patterns. Call your bank beforehand to set a travel notice.

How to hack flight prices using currency conversion

You can often lower your flight fare by setting your booking site's currency to the origin country of the airline. Use a VPN to simulate your location in that country and pay with a credit card that has no foreign transaction fees to maximize your savings.

Identify the airline's home currency. Look at where the airline is based. For example, if booking with Cathay Pacific, they are based in Hong Kong. Browsing their site in HKD often results in a different, sometimes lower, price than browsing in USD.
Use a VPN to match the origin. Connect your VPN to a server in the airline's home country. This prevents the booking engine from defaulting to your local currency based on your IP address.
Clear browser cookies. Always use an Incognito or Private window. Sites track your search history and location; if you search repeatedly in your home currency, the price may artificially rise.
Check the price on an OTA versus the airline direct. Once you have the 'local' price, compare it against aggregators like Google Flights or Skyscanner. Ensure you are comparing the final checkout price, including all taxes and fees, not just the base fare.
Use a 'no foreign transaction fee' card. When paying in a foreign currency, use a credit card that does not charge international transaction fees (usually 3%). Otherwise, the bank's fee will negate any savings you made by switching currencies.

Is this legal?: Yes. Airlines use 'dynamic pricing' based on point of sale. You are simply choosing the point of sale that benefits you most.
Why does the price change?: Airlines adjust their base fares to match the purchasing power and competitive landscape of specific markets. When you browse from a different region, you trigger those local market prices.
Will my credit card be declined?: Occasionally, a bank's fraud detection will block a purchase made in a foreign currency if it's unusual for your spending patterns. Call your bank beforehand to set a travel notice.