Just built a new computer maxed out everything except for RAM and the GPU.
I had 32GB of lovely 8GB DDR4 1Rx4 ECC'd Server grade DIMMS (stable and responsive). My plan to go crazy with 2nd hand server RAM went balls-up when turns out my over the top motherboard doesn't support 1Rx4, bloody brilliant! So stuck with a spare 4GB stick for now.
The GPU is just a spare one i have laying around (got 6 GPUs, 4 in computers). I will be swapping my old rig that has a Radeon 550 (equivalent to a GTX 1030, same gen as well)
So here is a lovely screenshot of my bodged computer, eith a top of the line CPU, motherboard, with only 4GB of RAM and a 9 year old GPU (and a Free Speech Flag to top it off)
Honestly depends on what are you going to do with your PC.
PC's have become really powerfull over the past years and with only a 2020 PC build can overkill a lot of stuff even in terms of servers.
As i said it, it will come to the factor of what are you going to do. Unfortunately the 2020 build are not going to "cut" well in terms of gaming.
Basically a workstation for professional development and gaming on the side.
End goal config is basically Xen base and 4ish VMs (when I get more RAM), Linux for Dev with whole of JetBrains Toolkit Running (also when I get more RAM), Firefox open with ~700 ish tabs avg open (when i get more RAM), Debian VM for Docker, automated tasks (compiling) and a rootkitted Windows VM on the side casual social gaming (solitare, chess, tetris, Fortnite, Ghenshin).
Maybe ML in the future when I am employed again and decided to invest in a GPU. Also video rendering with Blender (the best FOSS video editor, slightly better than shotcut) and handbrake (+ MakeMKV) for those DVD and Blu-ray rips (legal in the UK while in possession of original medium).