I have little sympathy for the OP. Airlines are there to make money. As part of revenue protection it might be wiser for the airline to leave J-seats empty to entice passenger to purchase J-tickets next time. If it too easy to upgrade, then why would passenger buy J-fares anymore?
US to AKL roundtrip can be purchased for EUR 3-4k if bought in advance.
but then it becomes reasonable for frequent flyers to investigate other airlines where that loyalty may be rewarded with better perks (such as upgrades that are more likely to clear).
Which other airline is offering a better upgrade programme for status passengers?