I can still see the logic for going for the 1080ti. How much was the 1080ti selling for? Was it 375 or 400? 2070S is is like £550 or if you're lucky £510?
A GPU at the end of the day to some is just a disposable PC component which you're probably going to replace in a couple of years.
The £150 you save, you can pump into games, RAM, an SSD etc.
Bit of perspective needed here I think.
I paid £375 for arguably the best version of the card with a phanteks waterblock. The card was bought new in January 2018 from OCUK.
Others have sold for £400 and £440 I think.
Let's not lump everyone into the "Ebay morons" bracket here because I'd argue it's equally moronic to spend upwards of a grand on what is effectively the 1080ti replacement. It's not twice the card, therefore not worth twice the price in my opinion.
Don't also forget the current demand and the current slowdown in manufacturing and shipping of new tech. You've also got to factor in the complete lack of competition at the high end allowing NVidia to basically price their cards at whatever they want. How much is the 3080ti and 4080ti going to cost?