It really depends on how you want to play it, as the requirement difference between 1080p single screen vs. Valve Index are massive. As opposed to most other flight sims, you'll want a GPU that is pretty close in performance to your CPU (which should be as powerful as possible). So essentially you want as good as you can afford / actually find in stock.

It's a bad time to build a flight-sim PC given the GPU shortage.

It's coming out for the XBOX Series S/X later this year, that might be the most cost effective way to play it.

The question will be whether the Series S/X version will run well enough to be worth buying.

I'll be keeping an eye on it. My dad always wanted to fly but never learned, and the latest Microsoft Flight Simulator has looked so impressive that I've debated whether a Series S/X and MFS might not be a fun gift for him to setup in the living room. Certainly more cost and space efficient, even if he only uses the console to play that one game.

>The question will be whether the Series S/X version will run well enough to be worth buying.

I also wonder whether the Xbox version will support all the HOTAS, yokes, pedals, and throttles that the PC version does. Some Thrustmaster sticks aren't compatible with consoles, for example.