The new GeForce GTX 1080 Ti has a launch price of $700 and that's exactly the same as the $700 charged for the GeForce GTX 780 Ti in 2013 -- and lower than the $850 demanded for the GeForce 8800 Ultra in 2007. The site also adjusted the prices for inflation and this results in the conclusion that today's GeForce GTX 1080 Ti costs almost exactly the same as the 17-years old GeForce 2 Ultra did at launch.
We have some notable fluctuation over the years, which mostly seems to coincide with when NVIDIA had true competition in the market place. When NVIDIA were on top, and the competition had nothing, the prices went up, as we can see with the 8800 Ultra. Other times, during periods of higher competition in the market, pricing was lower. You could argue that the 1080 Ti is actually under-priced for the market climate.