Originally Posted by number_6

I've never seen QF offer cash upgrades (like VS, BA, CX do on some routes, mostly to match VS). On QF you have to buy up the ticket, which means reissue to the new fare and rules. This takes time and wouldn't be possible at the last minute (as you board, for example). What sectors can be upgraded, or only one, depends on the specific ticket and fare rules, but there is no advantage over buying the upgraded class initially and it is likely to cost more. Not really a practical approach and current QF policies actively discourage it. QF is astonishing this way -- I was once on standby F, not an upgrade, and half hour before flight departure QF could not figure out how to charge my credit card (many thousands of dollars) and get me on the flight 30 minutes later. And that was in SYD (or perhaps because it was in SYD). Sometimes QF acts like it is a privilege to give them money, and be sure to do it at their convenience.