HTC Announces $549 Headset-Only Cosmos Elite (With Free Alyx)
https://uploadvr.com/cosmos-elite-headset-only/
>The full Cosmos Elite kit comes with the headset, the SteamVR tracking faceplate, two SteamVR 1.0 base stations and Vive wands controllers. Starting in April, however, HTC will be shipping just the headset and the faceplate for $549. That’s a huge reduction in price but, obviously, you’ll need some existing base stations and controllers to use it. It might be a feasible upgrade for existing-Vive owners, though we haven’t got final impressions for ourselves just yet.

Still more expensive than an Index HMD