I follow watch auctions for part of my work. If you need to buy new in a shop, fine. But if you're happy to buy at auction, you can save huge amounts depending on brand. Check out a company like Fellows, whose estimates tend to be spot on, and who shift a lot of stuff. Reckon on saving 40%-80% on one or two of the more "brandy" brands, and still get a watch made in 2015. For a laugh, check out the auction value of, say, Patek "your're not buying this for yourself, you're buying it for your offspring" Philippe. It's the Swiss watch industry's nightmare. Currently, Swiss watches devalue exactly like cars. Japanese high-end watches (which are cheaper than Swiss watches) depreciate somewhat less slowly. A Seiko celebrating 100 years of Seiko watches sold recently for around 1100 pounds, and in terms of attention to detail and engineering quality, is about as good as it gets (but it's not mechanical).
If you want to be sure your Swiss watch is 100% Swiss, you need to read up on the Poincon de Geneve certificate.
The nice thing about watches is there's really good stuff at every pricing point, once you get past the need to be seen wearing Omega or Rolex.
Piltdown Man's got the right idea: the best watch is the one which is a constant reminder of memories. Everything else is mostly Swatch Group managing brand "story".