Third-Party
Seems to be Viator pumping the cachback up to 17% again, same as this post except now it has a new expiration date of "in 2 days" (according to Cashwards).
Some of the lowest-cost or decent experiences that that I've found:
Sydney Harbour Bridge Self-Guided Audio and Puzzle Tour ++ - $7.80 (down to $6.50ish after cashback, up to 3 people)
Chinese Garden General Admission Ticket - $12 (down to $10ish after CB, per adult)
Australian National Maritime Museum Entry Ticket - See it All - $25 (down to $20ish after CB, per adult)
Sydney Tower Eye Ticket aka Centrepoint - $26 (down to $20ish after CB, per adult)
Behind The Scenes: Sydney Cricket Ground (SCG) Guided Walking Tour - $33 (down to $27.40ish after CB, per adult)
++ This is my listing on Viator and have avoided posting until a Viator cashback was offered also, including our introductory offer (as the listing is new to Viator)
I've only listed the Sydney ones, but it seems to be sitewide (so Australia wide also for anything listed there).
Enjoy!
Edit: Updated the names and formatting.
