It's on sale at Chemist Warehouse @ $12.99 - https://www.chemistwarehouse.com.au/catalogue#page=catalogue… (page 2) until 7 April.
So, head to Rejectshop and claim your 10% discount as per their "Lowest price guarantee".
To get the price reduced (from $19 to $11.69 - $0.106 per tablet), show this page at the register - https://www.chemistwarehouse.com.au/catalogue#page=catalogue…
Classic deal