I'd just like to point out that OP is either lying or has been scammed.
Starbucks have consistent pricing and the most expensive sandwich in the UK is £5.10, technically 5.25 for a plant based breakfast item, see here for full menu prices.
But people like getting angry at cost of living issues right now (understandably) so this will get hundreds of upvotes despite being a lie.
I've clearly eaten too many lunches from food vendors (including SB) inside convention centers because I expected see maybe 2 slices of ham and 1 of cheese for $8 (in 2023 money). And maybe a lettuce leaf that is probably a recycled hot coffee sleeve dyed green.
People giving money to Starbucks only tells them they can continue to charge what they want. I've never been a customer because coffee gives me the shits, but I'm constantly amazed to hear what people are willing to pay for a single beverage. Most Starbucks drinkers pay what I would pay for an entire meal drink included for their one drink.
I've been to a Starbucks once in my life and that was in August of 2012. I have never been back since I never plan to go back. I absolutely do not understand the appeal.
The parts I like are the attention to detail on the size of the bread being perfectly rectangular, the cheese slices being perfectly equally sized, and the consistently overlapping slices of ham that span the exact length of the bread. Then that all combines to form a shitty looking sandwich. Perfectly optimized sandwich designed by accountants.
Bought a cold sandwich at a quick-service place in England.
There's your problem. This one has a certain appeal, though. I'd pay eight pounds just to be spared the usual pile of cucumber slices, old egg, and obscene quantity of mayonnaise.