Why would you spend even £300 on something that tells you the time and the date?
Depends on how you think about it.
From the age of 15 (When I started working) til around 5 years ago, I went through a ton of watches - I wear watches all the time - to sleep, gym, footy games, out and about and they get scratched and broken. I have a load in a drawer - all bust/scratched/faulty etc. etc. Most watches I got were around £70-£100 each - not mad for a watch, I think you'll agree.
So in that time (About 23 years) - I spent (Given each watch only lasted around a year without getting knackered) around £2000 on watches.
Five years ago, I bought a Tag (With some money of my missus and money I'd saved) for around £850. It's a Tag, waterproof and more importantly it's got a Sapphire Crystal face so it can't be scratched (Unless you do it with a Diamond!) - I've had it 5 years (Which is around 4 years longer than any other watch I've ever owned) - if it lasts another 3 years then it's paid for itself. The metal is scratched to bits, but I couldn't care less about that. It's a decent watch that should (hopefully) last years. You get what you pay for.
I wanted a watch that would hopefully last a lifetime and would be worth repairing if it went wrong. It's already had 2 battery changes (None of my other watches ever lasted that long!) and if it broke, I'd pay to have it fixed. I was fed up of going through an endless collection of sub-standard cheap shite watches. Just wanted something good. It's also got loads of stuff on it (Tag Kirium) with digitial options on it (Although you can hide them). It's a quality watch at a high price. But one that's hopefully worth it.
Some people will pay £100 for a pair of trainers or £100 for a pair of jeans. I personally find that insane, but if they want to buy stuff that costs so much - then that's up to them isn't it?