If you compare it to two gen's ago: the 960 was $200 when it launched in January 2015 and the 980TI launched 5 months later at $650. The 980TI dropped below $200 around the launch of the 20- series earlier this year... so that's 3.5 years.
I'm not sure if that's a useful way of looking at it, and I know nothing about the demands of VR and even less about the whole RTX business. I think /r/buildapc/ and https://pcpartpicker.com/guide/ are pretty useful resources.