According to ITAD this is the all-time lowest price for the standard version of Battlefield 1.
The Revolution Edition is a bit cheaper on Amazon but it seems to be unavailable/out of stock - I have not tried using a VPN so maybe it is available then. In that case it is a bit cheaper there at about $20.19 AUD.
https://www.amazon.com/dp/B075TKKMKJ
Sale is until 21 June 9pm PDT.
Enjoy.
don't bother getting the standard edition if you plan to play online. you don't get all the maps and you don't get premium queue access.
new battlefield v will be out in about 5 months apparently