Hi,

I have a Ryzen 3600 with a 1070 which I use solely for flight sims (DCS and Falcon BMS). It works great although I wouldn't mind a GPU upgrade to get max graphics at 1440p. My main problem is that my son also uses it for his gaming with his friends and I don't really get a chance to use it except late at night. 

I was thinking of getting a used gaming PC for him without spending too much money. He mainly plays Roblox and Minecraft at the moment but is starting to branch out to proper 3D games as he gets older (he is 10). I was originally thinking of getting something around $500 (without keyboard/monitor etc) which would probably give him 30fps in 1080p but then thought if I spend a bit more (say $900) then I could get something a bit more powerful to give him 60fps and also get a GPU upgrade for my flight sim PC and he could have my 1070.

Does this sound like a reasonable plan for the money? Any ideas what a decent deal would look like? I don't really know the secondhand market, looks to be roughly a i5 10400 and a 2070 for that price. 

Any thoughts welcome, thanks.