Humble bundle has a nice steam bundle going on right now. For just $15 you get all of this
Gotham Knights
Back 4 Blood
Mortal Kombat 11 Ultimate
Mortal Kombat XL
Injustice 2 Legendary Edition
Mad Max
Batman Arkham Knight Premium Edition
Batman Arkham Origins
Batman Arkham City GOTY Edition
Batman Arkham Asylum GOTY Edition
Shadow of War Definitive Edition
Shadow of Mordor GOTY Edition
Gotham Knights
Back 4 Blood
Mortal Kombat 11 Ultimate
Mortal Kombat XL
Injustice 2 Legendary Edition
Mad Max
Batman Arkham Knight Premium Edition
Batman Arkham Origins
Batman Arkham City GOTY Edition
Batman Arkham Asylum GOTY Edition
Shadow of War Definitive Edition
Shadow of Mordor GOTY Edition