Well, my mother always used to say to me, if you have to ask how much it is you can't afford it.
SO yeah, the people that are in J class are either:
Bumped up from S class (because that is the cheapest upgradeable QF class) SHBB is about $2815 gross pls taxes
Rich mof_s who couldnt give a ****e about price
Corporate travellers or Entertainers who have it written into their contracts that they must fly QF J class AP (artists, musicians, politicians, bands, celebs, academics)
QF **** all over UA, the only other competitor giving them a run for their money on the direct route (NZ are fantastic) now are V Australia and of course they're a thousand times cheaper at the moment whilst they establish their name to steal business from QF. Once they are established I would expect the fares to be very comparable, I wouldnt fly delta if you paid me