Originally Posted by
skywardhunter
I don't think you can upgrade onboard for cash and not sure about upgrading mid-segment for cash either (i.e. your fare is AAA-DXB-AKL and upgrading for cash in DXB might not be possible for them to calculate easily unless there is an offer available for a discounted upgrade. As it is I'd keep an eye out for J Saver (O bucket) as from Flex Plus the additional cost might not be that high and sometimes savers do open up shortly before departure. With miles you can upgrade either in lounge or onboard, same miles cost.
I know you get some crazy price structures ex SA but even the going rate for the email upgrade DXB - AKL is 800 quid so I think the difference would still be quite a lot even from a Y+ to a business saver.