My installation takes up about 125GB on the chosen installed drive with a few folders and small files also created on the C drive. This is for the Premium Deluxe version and is now at v1.10.8.0. Update no. 6 is coming on November 10th.
Microsoft say you need minimum 150GB space but I didn't check what was used during installation... there may well have been a lot of temporary files on top of that 125GB.
Also, I've currently chosen not to cache any scenery but you can cache as much or as little as you have space for, so if you fly a lot in a particular area you can cache that area at any one of 3 levels of detail to minimise data downloads while playing. So if you happen to have an 18TB drive, you could easily fill it up.
(I'll move this thread to General if that's ok as Flight Sim isn't specifically Quest or Rift related and also doesn't yet have VR implemented).
Intel 5820K OC@4Ghz, Titan X (Maxwell), 32GB Corsair Vengeance DDR4, ASRock X99 Taichi, Samsung 500Gb 960 Evo M.2, Corsair H100i v2 Cooler, Inateck KTU3FR-4P USB 3 card, Windows 10 Pro v20H2 (19042.867)
