i have a I7 8700K for my cpu and im aiming to get a new graphics card around $500 USD. I want to aim for 1440p gaming at 144hz, Idk which is the bbest to buy. and also i could go used or new. Anything will help.
Do not get any used GPU though. The RTX 20270 is a good choice, but can you wait for few more months ? Because, Nvidia is going to release "refresh" RTX GPU lineup. These are going to be better binned chips, and having faster specs as well, with a lower price tag than the previous RTX cards.
I'm not sure fully about any ETA on the launch date, but it will be sooner, when AMD releases it's NAVI GPUs, IMO. Nvidia needs to counter this release by releasing "refresh" RTX cards, so these are indeed coming. There was also a rumor of an RTX 2070 Ti GPU being released, but we don't have any concrete info on this..