I am currently booked in fare class H (eco) ICN-SIN and I want to upgrade to business class using cash. This is an Air Canada ticket so when I called AC for the upgrade, they are quoting me an amount greater than a one-way ICN-SIN in business class, so it makes no sense.
Does OZ allow cash upgrades at the airport? If so, is there a way to have a rough idea of how much they will ask me to pay to upgrade from H to J for this route?