Nice watch, but how do you say that to a stranger?

[Lol-x]

I went out for a breakfast at an outside local cafe this morning.
I didn't have a watch on as I had been for a bike ride.
To my right was a guy in the company of his wife with a brand new Day-Date (118238).
I thought to say "nice watch" but I feared that everyone including him may have felt I was a little strange. You can't just say that to someone out of the blue.
So I forgot about it and resigned myself to keeping my feelings to myself.
Then just as he was leaving, for some reason I was talking about a completely different subject to a friend about how something was not a good deal or how something was expensive, like the price of seafood at the moment.
I said in a loud voice, "Yeah, just like buying a Rolex, what a rip-off!".
At that point I had sparked the interest of the stranger, maybe in the wrong way, but when he saw the smile on my face and my further explanation that I was an enthusiast, he poudly stated that he had only had his Day-Date for 4 months and was really enjoying it.
Anyway, I told him about my interest and suggested that I could go on but his wife was probably already starting to get bored.
It was a nice impromptu chat, and a great way to start the day.