@Jet Jetski - fascinating question and I agree with most of the comments made by others.
What I need to remember:-
Don't buy a watch you haven't tried on. I have admired Panerai watches on other peoples wrist but when I tried one on it just wasn't for me.
Don't buy on a whim. I bought a £3k+ watch while wandering round a shopping centre. Got it home and wondered why on earth I had bought it. Wore it half a dozen times and consigned it to storage.
Buy the watch you really want. If you can't afford it, don't buy something else thinking it will scratch the itch. Leave it until you find something affordable you really like.
Buy with your heart not your head. For months I have been looking at 2 watches that I have tried on. My heart says one but my head says go for the other. Buying both isn't an option and I really can't decide what to do.
For expensive watches buy preowned with box and papers.