You don't need a flight stick at all. Some of the games best pilots are using KB&M.
That said, to make KM&M work with a VR headset in a game with 100+ buttons (i.e. the inability to look at the keyboard) you'll need to invest in
Voice Attack and either set up the base system or pick up one of their cool compatible voice packs from
HCS Voice Packs and do a little less work. You'll need a microphone of decent quality, but once you memorize the commands to get the ship to do what you want by voice, things will work great.
That said, yes a good HOTAS is recommended since you can bind every button to a decent HOTAS system such that you'd only ever touch the keyboard for comms chatting. But those setups can be expensive and people will be quick to bring up their $150 systems, which are only affordable considerations for the hardcore. IMO, if you aren't sure this is a genre you know you you'll be getting 200+ hours out of, it's best to just get something in the $50 range or stick with KB&M until you know space/plane combat games are your thing. If you want to upgrade from there you can to something in the $100, $200, $300 or even $400 range if you like.
The stick used by Alfred in Batman vs Superman is one of our better HOTAs options. On the other side of the spectrum,
the Thrustmaster T-Flight HOTAS X is one of the most popular on the market. Go with your gut and look forward to a great game and experience.