I live in the Middle East. Local food here is cheap & delicious - we live mostly on vegetables, pulses & chicken cooked from scratch.
But I actually love baked beans, & when I see them in the local posh deli which is the only place you can get imported food, I treat myself to a £3.50 tin for a weekend breakfast. Yum.
ALL imported food is ridiculously expensive here. Everyone returns from visits back to the U.K. or Europe with at least one suitcase full of pesto/marmite/bacon/curry paste/marmalade etc etc. Spam is definitely a delicacy.
It's fine - we eat a much healthier diet - but we miss those imported treats & pay outrageous prices for them occasionally.
This is what living in a country with a food import problem looks like.
This is what the U.K. will almost inevitably look like.
Except the U.K. is also a net importer of food, so you aren't just looking at a few wealthy expats grumbling at the appalling price of a tin of beans; you're looking at stupid prices for staples.
If I were still there, damn right I'd be stockpiling. I'd be getting enough stuff in to avoid the supermarkets altogether for a week, & then long term I'd be looking at a garage full of all the 'nice to have' stuff I'd really miss.
& as everyone has already pointed out - if the worst thing that happened was prices only going up by a manageable amount, I'd have saved a few quid & no harm done.
I reckon unicorn steak will be pretty chewy, anyway.