here is a $300 budget Apu build for htpc/light gaming for games like World of warcraft, overwatch, league of legends, CS:GO, Armored Warfare, and a few others. Medium settings and 40+ fps mostly. may add a gpu later but for now i think this will do pretty well
https://pcpartpicker.com/list/jZZMLD
https://pcpartpicker.com/list/jZZMLD