Forgive the possibly stupid question, but how does one check reward availability on Qantas, so that you can buy (Equiv of) WT+ and upgrade to CW?

The BA site makes it so easy, but from what I can work gather you have to pay for you seat with Qantas and then hope that availbility might come up nearer the time.
Is there any way to look now for and have the results show like BA, as in 'There are 5 rewards seats left'.

I'm looking to fly from DXB to SYD/MEL direct.

TIA ^