Sydney Aquarium and Madame Tussauds

Hi guys,

I am looking at booking tickets to go to both the Sydney Aquarium and wax museum on the same day.

I found someone on Gumtree apparently selling tickets to go see 2 attractions for a low price of $35.

https://www.gumtree.com.au/s-ad/sydney-city/other-tickets/co…

How to confirm if this is legit or a scam?

Else, does anyone know the lowest price I can get tickets for now?

Thanks guys.