In case you missed the recent Steam deal here (like I did), it looks like EA still have the game on sale for $3.99 via the EA App. PS. Not sure when the expiry is for this deal.
"Biomutant (PC) is USD$2.99 on EA Desktop app (even cheaper if you got EA Play/Game Pass PC). Download the app here: https://www.ea.com/ea-desktop-beta includes standard game + DLC …