I've heard that more than once, but I never understood it. It just says how more are you willing to spend on a watch. A status symbol, if you wish, but nothing more. I understand a nice watch with a nice suit, but I don't attach any special meaning to it.
To me, it means you're willing to take time with the smaller things. And if you do that, it might be you are of a similar mindset in other parts of your life too.
To begin with, it probably means you're not wearing old rags for underwear, which you can't be bothered to change...

and if I were too tired to make dinner, you probably wouldn't buy ingredients for a sandwich, instead of delicate little bites of interesting things to make me smile...
Every single thing you do and say, says something about you...
Yeah, to many men don't take care to actaully look professional or look, not metro, but as if they've put some thought into their appearance beyond "Okay, this smells clean."
As a rule, I always go to a first meeting with someone in black dress shoes or polished steel-toes (depends on the enviroment), have one of my nice looking ballpoint pens, a silver wristwatch or a gold pocketwatch, and clothes in line with what is expected of the enviroment I'll be in.
Three things I in generally when I'm making a quick "guess" about someone who's a man and I'm having a meeting with.
1. Shoes -- Are they clean, in good shape? Tells me a lot of about whether a person is took the idea that their coming for a meeting or a job interview seriously. If they took the time to take care of something most people couldn't give a toss about, then I see that as detail oriented. Exception made if we're meeting at a construction site or a factory.
2. Watch -- A good watch lets me know that keeping track of time is important to them, but not to they're not so worried about busting up a $300 watch cleaning counters or doing actual work.
3. Ink pen -- as in having one, regardless of the type. Just something I used to work for in a employee. I always thought having a ink pen (or a pencil) was one of those things that says "okay, this person thinks ahead."
With women: 2 and 3 stay the same, but with 1 I look for shoes that are appropriate to the job setting. I lost track of the times that I interviewed people for jobs that meant climbing ladders or dealing with slick floors, only to have women show up in high-heels or open-toes; not good when you're talking hot popcorn oil, puke, or leaking bags of trash. More the annoying when you tell them on the phone "Show up as you would for a normal work day, cause if you're hired you'll start training tonight."