Joyce reckons they're only losing $20-30 on each ticket.
Isn't the J* seat cost per ASK something like 7.9 cents?
My great circle tracker shows it's about 822km SYD-MEL. That means that the 'cost' of each seat is about $65. I guess once you take out the QF subsidy then they probably are only losing $20-30. At least I now know how much QF is subsidising J* for!