Most airlines have in-town offices, it depends on where you live. They usually charge an extra cost for paying at the office.Thanks. I'm actually waiting to be approved for a debit card here w/ brubank... until then its all cash... but I have a flight I want to book ($300 current vs $100 blue) and pay with my blue rate... the issue is I can't pay online until I get the debit card. I'm thinking of trying to find a place I can get a visa gift card and give them the cash - then purchase the flight.... OR I uber to the airport and wait in a line to see if I can buy there. Fun stuff. If you have ideas let me know!
If your flight is international, the price in pesos (with the new taxes just added today) should be similar to the price in dollars (without arg taxes) at the blue rate exchange.
So you can book directly at the airline website with your US card in dollars. (choosing the US website version of the airline).