As I’d feared 
I might go to £50 as a one-off.
Out of interest, what would you pay to replace it if you lost it? That would really sting, right? Is metal card insurance something I should go and pitch on Dragons’ Den?
Given the reaction to £5/month, Monzo would have to pull something pretty incredible out the bag for £15/month. Nobody else has done this (especially as bundling travel insurance is verging on pointless at the moment).