VR Hardware is going to develop fast in the first years. You can not expect that what you buy now is going to be the best you can get for 2 years.
I would only buy it now, if I was satisfied with the current offer, could easily afford it, and would not mind better options coming out in the near future.
Me personally could not afford a new VR HMD every 2 years. I am also not entirely satisfied with the current state of VR Hardware and Software. Right now I would consider a Vive or Rift incl. Touch for 400-500€, but it's not worth 900€ to me. That's in the context of me having to save years for that amount of money though.
Overall I would like to wait for things to be more standardized. Maybe in a few years one tracking technology proves superior and future proof enough, so that it becomes a standard everyone uses. You could just combine any HMD and Controller.
Same on the SDK side. It would be great for consumers to have one open SDK that all VR Manufacturers support across multiple Platforms (e.g. Windows, Linux, macOS, Android). I do not want to be excluded from content because I prefer different hardware.
At this point it feels like the beginning of 3D Graphics cards with a lot of proprietary solutions, until Direct3D and OpenGL consolidated it all. It still sucks that Direct3D is Windows only, but at least there it works across a range of hardware.
I am aware though, that it all takes time to figure out, and you have to start somewhere. Having full control over the SDK is good for being flexible in trying out and developing new features.
I just don't want to spend my VR Budget on this yet, as I am confident there will be something much better in 1-2 years, and HMDs on the current gen level could drop in price significantly.
I would love to see a hybrid HMD, which I could use mobile by connecting it to a little VR box with a smartphone SoC, good cooling and battery life, and stationary with a high performance PC.
And of course there is the possibility of Wireless video, Foveated Rendering and higher resolution screens in the next 2 years, which would be significant improvements I would rather wait for.
I might consider low budget VR in the meantime. Maybe Google's Daydream turns into something decent and affordable for basic VR needs (like porn).