Guru3D is reporting the 2080 Ti and 2080 at release prices (I assume that means FE editions) of $899 and $699 respectively (USD). So if aftermarket AIB partners are asking $100 more for their variants, that would not be out of the norm. Also, just as a reminder, the GTX 1080 Ti and 1080 FE editions launched at $699 and $599 respectively, so the price gap has grown a little between the Ti and non-Ti. But my guess is the GTX 2080 will be faster than the GTX 1080 Ti.
So based on that, and if these new Turing-based 2xxx series hold up to their rumors in performance boost over Pascal, that extra $100 will be more than worth it. Especially with a single GPU and true 4K running GTX 2080 Ti that is almost certainly going to be faster than the Pascal Titan X. Keep things in perspective folks. One glaring omission here is the NVLINK technology which is the next level of SLI support that means two GPUs can share their memory for more bandwidth. Nobody knows what that will mean for games however if developers continue turning away from dedicating resources to coding for multiple GPUs.