If you want a big open world game, I can recommend Mad Max, you can find it in fanatical (a legal and trusted store) for $2.49. I had a lot of fun with it and it will give you tons of hours of fun.

www.fanatical.com/en/game/mad-max

I actually recommend you that site for steam keys since they often do bundles very cheap to help your library grow without spending a fortune.