The full-blown Valve Index Kit will set you back $999 and includes the headset, two wireless controllers, and two Lighthouse base stations. However, Valve will also let you purchase the components piecemeal, with the Index headset itself going for $499.
Speaking of the Index, it is still a tethered setup with an included 5-meter cable that plugs directly into your gaming rig. Valve is focused on high-fidelity VR experiences and thus has included dual 1400x1600 RGB displays (LCD) which can run at 120Hz (which is a critical advantage over competing OLED screens). According to Valve, 144Hz is possible, but that capability is currently in testing. The Index is still backwards compatible with games that were optimized for 90Hz displays.
Rather than using integrated headphones like some other designs, the Index incorporates dual speakers: they’re just setup to direct sound towards your head.
If you purchase the full-blown kit, you'll get two Index Controller, which were previously developed under the name "Knuckles." There are a total of 87 sensors in each controller that are able to pinpoint where you fingers are and what they're a doing. As such, you'll be able to grip, pinch, squeeze and make gestures (among other things) with you hands in VR titles. The Index Controllers will be available separately for $279 and are backwards compatible with previous Vive setups.
We should also mention that in order to take full advantage of a the Valve Index -- especially to match the 120 or 144 fps mark -- you're going to need a beefy gaming rig. We're likely looking at GeForce GTX 1080/1080 Ti, GeForce RTX and Radeon VII level GPUs along with a stout CPU to push those pixels. Couple that with the $999 price for the full Index kit and you're looking at a hefty investment to get the most of the VR experience.
Will it be worth it? We don't know for sure, but we can't wait to get our hands eyes on it to see how well it stacks to VR systems that have come before it.