Understand you prefer J, but Jetstar Max fares within QLD (e.g. BNE-CNS) or to Tasmania would probably be the best value at the moment in terms of $/SC.
BNE-MKY-ROK on QF is $199 in Y.
QF J fares are really not that great value at the moment. BNE-CNS for $726 (60 SC) or BNE-NLK for $719 (also 60 SC) is about as good as it gets on that front.
If you're a Points Club member (and have points to burn) then status runs using classic reward business class flights might be good value. The earn tables for such flights are here:
See how many Status Credits you’ll earn on Qantas marketed Classic Flight Rewards as a member of Points Club or Points Club Plus.
www.qantas.com
Not as many SCs as J flights paid for in cash, but then you're not paying cash (other than fees & taxes, though you can choose to pay for those in points as well IIRC).
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