I have a bunions and a wide-ish forefoot but a very narrow heel on a low volume foot that is 6.5/7. This means that a Euro 37 tends to fit me fairly well notwithstanding the size that Fly London says I should buy. I am a 37 in Danskos, and most Pros work for me but many Danskos do not. Topshop 37s work for me, but I think I am between sizes in ECCO.
I have the FL Ylva in gunmetal from a few years back. Very supportive and comfy, probably because of the laces. I bought the Yala a couple of years ago but ended up giving them to DD because they never stretched enough around my bunion.
The FLs are the most I have paid for footwear, and my sad experience with the Yalas make me a bit gun shy. I have my eye on the Yopps and the wedge sandals since they look a bit warmer than most sandals but I would only consider them if the price were right.
I wouldn't necessarily say that FL is overpriced. Maybe with Brexit the price will go down?