I just booked LHR-SYD return in J for 1050 SC (costing about £3500).
The full route is LHR-MEL-SYD inbound and SYD-BNE-MEL-LHR outbound. I'd already intended to book a return flight in J to SYD for work, but late last week I received an email from Qantas offering a 50% status credit bonus on all new QF bookings this month, so I thought I'd take the opportunity to add in a few extra J legs (for almost exactly the same price). It was 700 SC without the bonus. If everything works out as planned, the bonus should be just enough for WP.