I can confirm that this is absolutely true for LATAM Airlines. Booking a Brazilian flight (origin and destination within Brazil) is cheaper on LATAM's Brazilian

I can confirm that this is absolutely true for LATAM Airlines. Booking a Brazilian flight (origin and destination within Brazil) is cheaper on LATAM's Brazilian portal than on LATAM's USA portal whenever I've compared them. You don't need a VPN: just look at latamairlines.com/br/pt vs latamairlines.com/us/en. Ahh, but they are very sneaky. The Brazilian site only accepts payments with credit cards issued by Brazilian banks. They won't accept credit cards from the USA or other countries. You have to use the USA portal or international portal of LATAM if you want to pay with a non-Brazilian credit card, and you'll pay more for the exact same flight.