[Catfish]

I just had to re-install Win 10 with some programs since my boot 'disk', a six-year-old Kingston SSD with 240 Gb, died.
I prefer those solid state disks meanwhile, they seem to work as long as normal HDs, but are way faster. They are also more expensive, but.. depends:
Bought a 500 Gb Samsung Evo for 80 Euros, also much faster than the old Kingston. Booting up Win 10 with all bells and whistles takes 10-12 seconds, shutdown appx. the same. I put all sim games on the SSD, and they runs smooth as silk.

Still have an older 4-core i4 working, at 3,8 GHz and with 16 Gb ram, with an old Nvidia.
Indeed i will rather get a faster graphics card than a new PC ..

Still use a normal mechanical HD for data, photos, correspondence and the like, and an external one via USB3 for backups. The latter one is easier in case than using the off-room NAS.

Go for a fast processor (3.8 to 4.7 GHz), the number of cores is not (yet) mandatory; few programs and games can use more than 2 anyway.
And use a good/fast graphic card.

If you use HighTec 3d-building things like Solidworks it will still do fast enough.