This is the Woolies site for purchasing the COVID-19 rapid antigen tests. They are $50 but if you sign up for their newsletter AND create and account you get free delivery (normally $10) and a $10 discount code emailed to you making the delivered price $40. Plus if you sign up you can also get 40 woolies rewards points.
There are lots of places out there selling 5 for $60-$80 so at $40 delivered it seems like the best price around.
Note : They only ship from 4th November.