Considering REX don't fly SYD-PER I would say the muffin probably costs a hell of a lot in that light. Needless to say the SYD-PER segment isn't free thus to figure out how much the muffin really costs one would have to compare a CBR-SYD-PER airfare travelling REX/QF vs REX/DJ. Since QF have an abundance of capacity at the present I would say it is probably close. But I can assure you QF do not sell anything, or provide it "free", that is anywhere near as good as a DJ chocolate muffin. You haven't indulged until you have one of these delectable items.