Well said.But your not comparing like for like. A RX Vega 64 liquid edition comes with it's own self contained water cooler where as the 1080Ti comes with a conventional heatsink and fan design. The Vega 64 is around 1080 performance so if a RX Vega 64 costs £650 with an AIO how much does a GTX1080 costs with an AIO? Well looking at the store the Gigiabyte model costs exactly the same.
If you want to moan about pricing then you should be pointing out that you can by an el cheapo GTX1080 for £450 that has a blower style cooler whereas the cheapest RX Vega 64 start at around £548 that has a similer style cooler (the RX Vega might have vapor chamber on it though).