I would get a brand new headset from valve if I were you cause its going to be worth more to sell all of your stuff as a complete set in the future if you need to vs an old vive with that stuff.
Would only cost you a hundred more than you bought the used one for and its worth it cause Index is still the best VR experience you can get at the moment imo.
Listen, ill be real with you, its basically unusable and unreliable in most scenarios. The technical reason for this is due to Wayland vs X11 and other underdeveloped display technology. Normal gaming just got good enough after years of work. And before anyone tells me that the Index does work on Linux, it sure does just not well at all.
I have since sold my Index but when I used it, 80% of it was on windows. Be on the lookout for something called the Valve Deckard. I believe thats when Linux VR will finally be ready.
https://github.com/y4my4my4m/kde-shader-wallpaper only for KDE though
Oh damn yeah it must not be available in your country right now sorry. I just assumed if it was available for us mericans it would be for everyone else :(