I'd wait for the latest RTX 40xx cards for sure.  And with that we may need a different power supply (but hopefully not and hopefully there will be adapter cables)

Also - I'm not sure what Intel is cooking up, but that new AMD 5800x3D cpu is amazing.  The best for MSFS so far.  AMD also has the series 7 on the way.  I know if we always wait we'll never have anything but I'd hold off till this Fall for sure.  Especially because we've heard reliable rumors that the 40xx RTX cards will be far more powerful than the 30xx's.  I saw a leak where the 4060 was better than a 3090.

I just built a 12700K / 32GB ram ddr5 / Z690 setup for just shy of 2k USD (kept my GTX 1080 Ti) - I'm getting about 25 fps at 1440P res with ultra settings and clouds/payware airports.  Very rarely does it dip below 20.  In the countryside or outside of photogrammetry it's usually 30-60 fps.

I also echo micstatic - get 32GB ram.  If previously you only had 8 and you found a cheap deal to go to 16...sure I I'd do that.  But for a brand new build...  32GB all day long.  I always have browser tabs, multiple apps running at once plus MSFS...  my record so far was 26GB used in total.  MSFS tends to use about 14-16 GB by itself.

So yeah... I'd hold off till Fall.

Ryzen 7000 Retailer Pricing Shows Big Hike Over Ryzen 5000 | Tom's Hardware (tomshardware.com)

Newer AMD Ryzen chips have SQUIP vulnerably (guru3d.com)