Many "horologists" or collectors look for vintage pieces to restore or add to their collections. They may buy directly through forums or local community groups.
These are often the best for luxury brands like Rolex or Patek Philippe. They have in-house experts who value the watch based on market data, rarity, and condition.
Most local jewelry stores buy watches for resale. If the watch is made of precious metals (gold or silver) but is broken or from an unknown brand, "cash-for-gold" buyers may purchase it for its scrap value.