Aren't we supposed to be at the start of another cycle of consumers being hard up? Car sales down, property prices dropping.
Might it be that an £800+ phone (from any company) just doesn't represent a good value for money choice for most people who still use phones for speaking, texting, navigation, social media and taking photos. All things that can be done well on a £80 phone these days.
So what are you getting for all that extra money? A lot more shiny, a bit more speed and a thing you can wave under someone's nose as a demonstration of wealth. Basically meaning that a great many people who buy very expensive phones are pricks. Making the phone an indicator of wealth, possibly stupidity and prickishness. Those who actually need powerful phones and are not pricks will be tarred by association.
So I think the majority of these hyper-phones will undersell and they'll remain a small niche.