When pre-owned makes sense
Pre-owned is almost always smarter for hot references that you can't get at retail. The Royal Oak, Nautilus, Daytona, and most Patek/AP/Vacheron sports watches sell 1.3-2.5x retail on the grey market because authorised-dealer waitlists are 2-4 years. If you want one and can't or don't want to wait, the secondary market is the only realistic path. For less-hyped references (Datejust, Speedmaster, Aqua Terra), pre-owned saves 10-30% off retail with no real downside.
What to verify
Authenticity: serial numbers, hallmarks, dial alignment. Use brand-specific authentication services for high-value pieces (Watchfinder, Bob's, Chrono24's verified buyer programme). Service history: if it was last serviced 7+ years ago, factor a CHF 600-1,500 service into your offer. Box and papers: 'full set' = original box, warranty card, manuals. Adds 5-15% to value at resale; missing papers can knock 10-20% off.
Where to buy
Chrono24 is the largest pre-owned marketplace with verified-buyer protections; ~700,000 listings at any time. WatchBox / Govberg / Hodinkee Shop are dealer-driven, higher prices but better authentication and warranty. Bob's Watches specialises in Rolex with strong inspection. Watchfinder (UK) carries a 24-month warranty. eBay can have great deals but requires careful authentication; the eBay Authenticate programme covers most luxury references.
Red flags
Avoid: 'too good to be true' prices (often replicas or stolen); sellers without recent feedback; references with no movement photos; condition descriptions that are vague ('polished a few times', 'minor scratches'); demands for bank wire transfer; pressure to skip authentication. The pre-owned market has plenty of legitimate sellers; if any of the above appear, walk away. See how to authenticate a Rolex.