First of all you have to understand that the Valve Index, just like the HTC Vive and the Pimax for example, is a complete system that connects to your PC.
So this means the box will contact the VR headset itself, 2 tracking stations and 2 hand controllers and small stuff like cables.
A nice touch is that the package comes with a download voucher for the above mentioned AAA VR title Half-life: Alyx, which will release in march 2020.

Obviously this is partly why it’s so expensive. But it also makes for quite a poweful VR headset. And at the same time this might also be the reason why you don’t need it.

You really need to ask yourself: What do I need the Valve Index for. Maybe i’m better of with a much cheaper wireless VR headset like the Oculus Quest!
Are you planning on playing many VR games, especially the ones with high quality graphics? Are you going to use powerful VR apps?
Or is the only reason why you are here that you want to watch the best VR porn and that’s pretty much it?

If you only care about the VR adult movies stuff then the Valve Index is not for you.
Unless you got more money than you know what to with 😉
But really, there is no real reason to buy one. It’s too expensive and has too many options and takes too much space if you only want to watch movies. And also remember that you’re always attached to your computer with a cable.

If you always watch your porn behind your computer anyway then that’s no big deal but some people prefer to watch it in bed or other places. Then I’d really suggest buying one of the wireless VR headsets.