Originally Posted by
samjnz
You could probably re-ticket the fare and use the credit later (minus the change fee).
Did you mean cancel/credit the higher fare (less cancellation fee), and buy the sale fare?
Always an option, but the recent increase in cancellation fees means that the sale would need to at least be cheaper than the fees.
And some sale fares will have a reduced SP earn, and are not upgradable (F class) - both factors to consider.