Wait for HBM2 or go for GDDR5X?

I want to build a PC; I can spent up to 3200 $ and I'm gonna use it for at least 4 years (been using my current PC for 5 years now).
I've been waiting for Pascal GPU's for almost a year now but as it turns out the upcoming GTX 1070 and 1080 won't be using HBM2 which is supposed to be (or at least I thought it would be) one of the best features of Pascal (if not the best) and will offer GDDR5 & GDDR5x instead. I read somewhere that the first HBM2 capable gpu (Tesla P100) will be available Q1 2017.
I can wait for Tesla P100 or any other card that supports HBM2 till Q1 2017, but will it cost as much as 980 ti or slightly higher price (lets say 10-20 % price increase)? Or is it gonna cost astronomical like 3 times or 5 times the cost of current high end GPUs (which I won't be able to pay for and therefore will have to go with GDDR5x) ?
Also is HBM2 really that good compare to GDDR5x?

 

You can bet the first consumer nvidia GPU to get HBM will be a titan, and will be priced accordingly. Don't expect the first HBM nvidia gpu to arrive before 2017 or at the 980ti price point

 

I second that.. I don't expect a HBM2 GPU from NVIDIA before AMD tbh... I expect AMD to have dibs on HBM2 first..

 

Ok but will it cost around 1000$ like a Titan x ?

 

Possibly. Or it could be absurd like the Titan Z when that came out. I'm thinking more Titan Z type pricing on launch, knowing nVidia....

 

In that case I'd go with gtx 1070/1080

 

Probably the smarter choice.. SLI if you want better performance too..