Monte Cook Games have a 50% off sale on the full range of their kids tabletop RPG No Thank You, Evil and the starter set of their teens/adults' tabletop RPG Numenera.
No Thank You, Evil gets good reviews and is aimed at kids and adults 5+ https://boardgamegeek.com/boardgame/208428/no-thank-you-evil
I bought the full set which included the base game and the three expansions for US$57.50 + US$13.17 shipping (US$70.67). Total cost was AU$113.42 using PayPal.
Best price I could find in Australia for the core set of No Thank You, Evil was AU$56.49 + AU$10 flat rate shipping. The expansion sets seem to be difficult to come by in Australia https://www.boardgameoracle.com/boardgame/price/no-thank-you...
Numenera seems to use a similar core system to No Thank You, Evil, but is aimed at teens/adults. The starter set is currently US$12.50.