David Jones has lots of lego on sale, and now has an additional 20% off as part of its EOFY sale. There is no set end date for the sale and the fine print simply says "late June".
Looks like it is retired and soon to retire sets only, not the newer lego sets.
https://www.davidjones.com/product/lego-super-heroes-black-p…
https://www.davidjones.com/product/lego-lego%C2%AE-%C2%BF-di…
https://www.davidjones.com/product/lego-lego%C2%AE-super-mar…
(Don't forget to also try claiming cashback. Not sure if it will be accepted given the 20% off, but worth a try!)
Qantas is currently doing 10 points per $1 on David Jones gift card as well