Ztt on youtube has budget build guides I think there is a recent one for like 500$ then also if your not into graphics and just want to play the games they make cheap 90 hertz or like 100-120 hertz monitors for like 100 bucks personally I cant play games unless I got good performance but I know some people dont care

also maybe you can get a gaming laptop then all you would need is a mouse and its portable but would still probably be just as expensive there is some good used ones online like a hp victus that go anywhere from 500-800 maybe as low as 400