There's some very good WT+ fares around currently ex LHR to oz for about 1500 quid, there's a thread on it a couple of days ago.

In the instance of a decent WT+ fare it's best to leave ex London as the EXEU fares tend to only work out a good option if your flying CW upwards.

Another thing to consider if booking London-oz is that you can book online as two outbound flight numbers and two on the return which I think still gives a slightly higher number of tps when compared to a direct flight number.

Also book this routing on qantas but on the BA flight numbers as it's considered on the board that qantas premium economy is better than BA's but by booking on the BA flight number you will still get the full dollop of miles as if it were a BA flight.

If your going to go down this route put all your flying onto oneworld airlines. And credit to BAEC.

Finally have fun & happy flightings.

cs