I think Scorpio will be out in less than a year.
$399.99 next summer in time for Madden NFL 2018.
6 TFLOP is nothing that mind blowing for 2017, it's a good better better than what Sony is offering but that doesn't make it budget breaking.
A Polaris 11 is a cheap GPU and it's 5.5 TFLOP right now, MS just can use an overclocked version of that.
I think RAM differences will be more interesting actually, if MS goes to 12GB or 16GB.
We've had 8GB for a long time now, the price should be down after 4 years to increase to 12GB or 16GB.