Well, I do find it possible to understand spending a lot money on a flat in Knightsbridge. After all, you can then live in it, and the more you spend, the better flat you get. It's also, potentially, an investment you can resell, and maybe even make a profit. It makes sense that a banker would think in those terms.
I also find it possible to understand spending a lot of money on a fancy car, though I'd never want to do it myself. After all, you can then drive it, and the more you spend, the better car (roughly speaking) you get, or at least I assume so. Admittedly, cars depreciate rapidly in value, so it's not much use as an investment, but in the meantime you can feel the wind in your hair.
What I can't understand is why people would spend thousands of pounds on a Rolex watch. After all, you can buy a watch that will keep perfect time for, say, £30, and your Rolex won't do a jot better job of being a chronometer. Nor can you expect to resell it at a profit. The only point of a Rolex, as far as I can see, is to let people know that you're