Was in the area so had a quick squiz...

Big W Stafford City as of 5:30PM yesterday had:

Toy Isle near registers - 3x $15 Blitzwing, 6x $15 Octone, 1x MB Grimlock, 2x MB Blackout
In the actual toy section- 2x $10 Krok, at least a dozen each of $5 Cosmos and Seaspray.

I did not see any POTP leaders...

I didnt search the whole store so there may be other isles that have transformers in them knowing Big W and the way they like to spread stuff around the whole store for their sale