Read the Listing Before You Read the Price
A Breguet Classique 7137 offered far below the pre-owned market is one of three things: a replica built on a generic calendar module, a genuine watch with a swapped movement, or a listing that collects a deposit and ships nothing. Decide which one you are looking at before you discuss money. The rest of this guide assumes two paths. A working perpetual calendar at a discount means a replica. A watch that holds value and can be serviced means a pre-owned original with paperwork.
The 7137 is a perpetual calendar in a gold case of roughly 39 mm, with a retrograde date and a moon phase. Replica makers copy the dial layout and the case shape. They rarely copy the calendar mechanics. That gap is where you do your inspection, because a calendar that stops, drifts, or needs manual correction at every month end is the single most common failure in this price bracket.
Prerequisites
- Written reference data: case metal, case diameter, movement calibre, and dial layout for the exact variant you want.
- A payment method with chargeback rights. Never wire money to a first-time seller.
- A return window of at least seven days, confirmed in writing before payment.
- One hour at a table with good light and a loupe or a phone macro lens.
Step-by-Step Evaluation
- Ask the seller to state the full reference number, case metal, case diameter, and movement calibre in writing.
- Compare those four answers against the published specification for that reference and end the conversation on any mismatch.
- Request timestamped photos of the case back showing the movement, the hallmarks, and the serial engraving.
- Ask for a short video of the date hand sweeping through a month change with the crown pulled and turned.
- Test whether the calendar is truly perpetual by setting it forward through a non-leap February and confirming it rolls to 1 March without correction.
- Check the moon phase disc for a smooth 29.5 day cycle rather than a 31 step jump.
- Confirm the case metal with an XRF reading or an acid test if you can inspect the watch in person.
- Study the dial under raking light for machine stamped patterns that lack the depth of hand turned guilloche.
- Ask when the watch last received service and who performed it, then ask for the invoice.
- Total the landed cost: item price, shipping, insurance, import duty, and any currency conversion fee.
- Pay with a card or an escrow service that holds funds until delivery is confirmed.
- Inspect the watch within the return window and repeat the calendar test before you leave feedback.
Parameters That Set the Value
- Calendar type: perpetual, annual, or a simple triple date with a fake moon phase.
- Movement origin: a named calibre with visible finishing, or an unmarked module hidden under a solid back.
- Case metal: solid gold with hallmarks, gold plating, or steel with a gold wash.
- Dial finish: engine turned guilloche, printed pattern, or a photo that hides the difference.
- Documentation: box, papers, and service records add more to resale than any cosmetic upgrade.
- Seller terms: stock photos, no return policy, and pressure to pay outside the platform.
Pitfalls to Avoid
- An annual calendar advertised as perpetual. It will need a manual jump every February.
- A quartz or battery movement behind a decorated rotor plate.
- "Swiss made" printed on a watch that never saw Swiss production standards.
- Customs seizure. Imported counterfeit watches can be destroyed, and the buyer usually loses both the goods and the money.
- Wiring funds to a seller who only exists in a chat app.
- Buying from photos of someone else's watch, which is the most common form of this scam.
Before You Pay
Write down what you are buying, what it should do, and what happens if it does not. A seller who answers every question in detail is worth a small premium. A seller who rushes you toward a payment app is not worth any price, no matter how low the number looks on the listing.