I've only built one gaming rig, and that was in fall 2014. I actually don't even really play modern games tho so I didn't need to go full all out, but even then it's really lasted me until now (only real upgrade is switching to a gtx 970 ... bought the damn rig like a month before the 9 series came out, like an idiot) and the only reason I even have to upgrade is wanting to push up to at least 2K.
I'm definitely waiting until the 11 (or whatever) series but I'm not sure if I want to wait for a new line of CPUs as well, that might push me to having to wait until Black Friday 2019 rather than spring 2019 I was hoping for. Just ... if I do wait until fall anyway I might even be able to shoot for 4K monitors in my price range.
Right now I'm hoping I can do 27", 2K resolution, 144hz refresh, 1ms response for my main/game monitor and ideally the same for the second window but I could live with 60hz refresh on the that one ... looks like it's probably over 400 to do that now, I wonder if you could do 32" @ 4K for around 350 on a black friday sale in 2019 ? Oh dang, I just looked, apparently they don't even make 4K 144hz monitors right now ? Yeeaaah they wouldn't be affordable by next year ...
Yeah, looks like shooting for solid/stable high fps at 2K might be by far best bang for the buck.