my friend will only play 1-2 matches per day . He only plays cs go,valorant and fortnite. So over 100 fps in those games are totally fine. he has 75hz monitor and 120 gb ssd already.
I mean he has money but he only want to play those 3 games for max 1-2 hour per day. he is thinking about paying $250 .
ddr3 mbo's are fine.
any old AMD, intel cpus are fine.
any old gpu is fine. ( i heard that some amd gpus are used widely for mining purposes so buying used amd gpu could be risky. so I'm thinking about gtx 1050ti since good performance on those games and low power consume).
maybe I am misremember so I recommend you double check, but even at that usage until it breaks performance still should be similar as out of the box (not exactly the same). Tho you should check how long they have been used aswell because ofcourse one used for 1 year will "live" longer than one being used 3+ years. I do think that even at 3 years it should last long enough (I guess tho).
For that money I think the best way to go is find a used machine someone is selling, there should be plenty of choices. If you find the right forum you may even want to post a "Will buy" ad and see what people offer.