I've been aware of things people take for granted when they suggest something is 'cheap' when many people would have to budget/save for it.
My oven broke when I'd just wiped out almost all of my emergency fund on unexpected vet bills that my insurance didn't cover. While I was looking at second hand ovens, arranging someone to collect it and finding an affordable gas fitter to put it in - "why don't you just buy this cheap £650 one to tide you over?"
No idea that some people might not have immediate access to such a 'small' amount of money (or that I would have chosen the ease of having something new with delivery and installation included if I could).
Being invited on a 'cheap' last minute girl's weekend - "it's only £900 then you'll just need a bit of spending money!"
£900 on flights/accommodation just for myself would be my only holiday that year, and I'd have to save for it.
You see where people take things for granted when they assume that what's cheap to them will class as cheap to most people.
The watch discussion is tedious, but demonstrates that blindness. Somebody saying that they're wearing an 'expensive' £400 item is saying that this item classes as expensive TO THEM. It's something they couldn't casually replace if it was lost, it's not an amount they would or could usually spend.
It's not saying this item is top of the range. It's not saying "this would be expensive to everyone".
Having somebody pop up to announce that somebody's expensive (to them) item is cheap ("what's next, a £50 handbag is expensive? 🤣🤣🤣" - to folk whose usual budget would be £15, yes it is!) is patronising, tone deaf, braggy, and a perfect example of people taking their privilege for granted.