>>716186617 (OP)
For the monitor, you need to choose between OLED for color quality and motion clarity or LCD for variable refresh rate and longevity for general non-gaming use. Or maybe get one of each. There's no reason to choose other types when you can get a good OLED or LCD with adaptive sync + at least 144hz for under 500 bucks. Don't buy any LCD without variable refresh rate.
You can get a perfectly decent mechanical keyboard for 40 bucks. I recommend linear switches. The most "gaming" keyboards you can get are the optical slide switches like the ones wooting makes, but honestly not important to upgrade that much.
For gaming mice the main thing is it fits your hand well and lighter is better. I can recommend Zowie as a brand that is comfortable but well liked by pro gamers. The main reason I like it is just that you can change the settings by pressing buttons on it and not having to download gay bloat software.
Finally I want to mention your speakers or headphones are just as important as your monitor. Maybe moreso considering your PC and monitor will be upgraded over the years but you can use your speakers for several decades, so it's worth spending on good ones. You can also get good used ones pretty cheap if you keep an eye on local listings.
I won't tell you what speakers to buy; I have no idea because I build my own and I could only recommend drivers to buy.
For my headphones I use the 7hz Zero 2 IEMs and Jcally JM20 dongle. really good sound for $50. IF you can stand having them shoved in your ears for hours on end.
