Why is the Rolex so expensive, are diamonds involved?
Its a combination of craftsmanship, style and of course the name.
A high quality automatic Swiss watch will last you the rest of your life with proper servicing.
Is 7k+ an acceptable price to spend on a watch simply because you will never have to buy another watch in your life if you don't want to? Absolutely not.
But, it is the combination of all three that make it a worthwhile purchase for some. I don't own a Rolex, yet, but I do have watches from comparable watchmakers though.