Re: the GPU, keep an eye on power consumption specs, unless you’re on a flat rate.
A 3060 12GB has more ram, performs better, has DLSS, needs less power than the 1080. It may cost 50 dollars more on the used market, but it’s a better value, imho.
Re CPU/RAM: you can probably find a good deal on a Motherboard + CPU/RAM combo on the used market, without breaking the bank.
As people move to new gen chips, lots of good deals on very good hardware are available.