Carnaxus :
You should probably still plan to upgrade everything else; most of your components are a bit out of date. You'd see a major performance improvement even just going to a 970 from that 770, and the 970 isn't even the latest.
He already have those pc. After adding the ram (around $40), it should run with appropriate adjustment, why bother upgrade it. Not all people can easily do $200 upgrade. The 770 should still be able to play those game. The battle between AMD (RX 580) and Nvidia (GTX 1060) is still ongoing, better wait a better deal and optimize that 770 in the meantime.
i5 starting to get out of date but it seems he bought the unit not long ago (i5 7500). My office pc with i5-2320 (4x4Gb ram, RX 480 4Gb, SSD 240Gb) which much older than his are still capable of playing Battlefield 1 on 1440x900 (limited by cheap monitor) ultra setting with no problem. My cpu clearly bottlenecked the gpu, but considering the result, its still satisfied some people like me.