u could spend ~200$ and get a ryzen 2200g + cheapest mobo + 8gb ram

or save up / get cpu now and gpu later

or look for used system if u dont wanna spend more 150

Grab a Xeon e5450/5440 quad core and a mod sticker then use an exact-o knife to modify your socket, should cost ~$10 total. Cheapass cooler for $5-$10 to crank the sucker to 4+ghz, 2x2gb more ram for $10. Used gpu like gtx 750ti, gt 1030, rx 460, gtx 1050/ti or something more power hungry If you have a decent PSU, like an rx 580 for $99 used.

with his resolution that wouldnt be bad