Top end watches almost invariably have automatic movements so don't need battery changes. You don't see Patek Philippe's current range needing batteries, or Rolex for that matter.
Also, a good watch will depreciate a lot in the first few years but after that very slowly, if at all. So best to buy second-hand from a dealer.
I've got a Rolex Datejust for formal wear and an Omega Seamaster Professional Chrono Diver for 'casual'. Haven't used it for diving yet but it's got a helium release valve - essential if you're doing week long saturation diving trips
Certainly won't be rushing to buy a Brietling any time soon after reading this thread.