{"reference": {"slug": "iwc-iw504101", "brand": "IWC", "ref": "IW504101", "model": "Portuguese Sidérale Scafusia", "case_material": "Platinum", "provenance": "extracted_from_auction_comps", "url": "https://mostexpensivewatches.net/reference/iwc-iw504101", "description": "The IWC Portugieser Sidérale Scafusia reference IW504101 was introduced in 2011 as a built-to-order flagship and remains the most complex timepiece in the brand's history. Production is extremely limited due to the bespoke nature of each piece, which requires approximately one year to manufacture. The watch features the manual-wind caliber 94900, incorporating a constant-force tourbillon, a 96-hour power reserve, and a unique celestial display on the caseback customized to the owner’s specific geographical coordinates. The 46mm platinum case houses a dial displaying both solar time and sidereal time. Collectors value this reference for its astronomical complications, including a perpetual calendar and sunrise/sunset indications. On the secondary market, these timepieces typically command prices in the mid-to-high six-figure range, often between $350,000 and $500,000. A notable aspect of production is that no two examples are identical because the star charts are calibrated to individual locations."}, "listing_stats": {"count": 4, "median": 6600.0, "low": 5300.0, "high": 9750.0, "brands": 1, "merchants": 1}, "listings": [{"id": "h_8695738171571", "title": "IWC IWC Pilot’s Chronograph C.03 (Pre-owned)", "brand": "IWC", "model": "IWC Pilot’s Chronograph C.03 (Pre-owned)", "reference": "—", "price_usd": 6050.0, "currency": "USD", "condition": "excellent", "box_papers": "full_set", "year": null, "case_material": "Stainless Steel", "case_size_mm": 41.0, "movement": "Automatic", "complications": ["Chronograph"], "merchant_slug": "collective-horology", "merchant_name": "Collective Horology", "image_url": "https://cdn.shopify.com/s/files/1/0559/0623/8643/files/P9176723-2.jpg?v=1789676341", "detail_url": "https://mostexpensivewatches.net/listing/h_8695738171571", "buy_url": "https://mostexpensivewatches.net/out/h_8695738171571", "alt_buy_urls": [{"partner": "goldsmiths", "name": "Goldsmiths", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_8695738171571/via/goldsmiths"}, {"partner": "selfridges", "name": "Selfridges", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_8695738171571/via/selfridges"}, {"partner": "farfetch", "name": "Farfetch", "region": "Global", "url": "https://mostexpensivewatches.net/out/h_8695738171571/via/farfetch"}], "available": true}, {"id": "h_8049503994035", "title": "IWC IWC Pilot's Watch Chronograph 41 TOP GUN Ceratanium IW388106 (Pre-owned)", "brand": "IWC", "model": "IWC Pilot's Watch Chronograph 41 TOP GUN Ceratanium IW388106 (Pre-owned)", "reference": "—", "price_usd": 9750.0, "currency": "USD", "condition": "excellent", "box_papers": "full_set", "year": null, "case_material": "Stainless Steel", "case_size_mm": 40.0, "movement": "Automatic", "complications": ["Chronograph"], "merchant_slug": "collective-horology", "merchant_name": "Collective Horology", "image_url": "https://cdn.shopify.com/s/files/1/0559/0623/8643/files/IMG_2055.jpg?v=1736883349", "detail_url": "https://mostexpensivewatches.net/listing/h_8049503994035", "buy_url": "https://mostexpensivewatches.net/out/h_8049503994035", "alt_buy_urls": [{"partner": "goldsmiths", "name": "Goldsmiths", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_8049503994035/via/goldsmiths"}, {"partner": "selfridges", "name": "Selfridges", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_8049503994035/via/selfridges"}, {"partner": "farfetch", "name": "Farfetch", "region": "Global", "url": "https://mostexpensivewatches.net/out/h_8049503994035/via/farfetch"}], "available": false}, {"id": "h_7300577755315", "title": "IWC IWC Pilot’s Chronograph C.03 for Collective (Sold Out)", "brand": "IWC", "model": "IWC Pilot’s Chronograph C.03 for Collective (Sold Out)", "reference": "—", "price_usd": 7150.0, "currency": "USD", "condition": "excellent", "box_papers": "full_set", "year": null, "case_material": "Stainless Steel", "case_size_mm": 40.0, "movement": "Automatic", "complications": ["Chronograph"], "merchant_slug": "collective-horology", "merchant_name": "Collective Horology", "image_url": "https://cdn.shopify.com/s/files/1/0559/0623/8643/products/IWCFrontCropped.jpg?v=1667877632", "detail_url": "https://mostexpensivewatches.net/listing/h_7300577755315", "buy_url": "https://mostexpensivewatches.net/out/h_7300577755315", "alt_buy_urls": [{"partner": "goldsmiths", "name": "Goldsmiths", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_7300577755315/via/goldsmiths"}, {"partner": "selfridges", "name": "Selfridges", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_7300577755315/via/selfridges"}, {"partner": "farfetch", "name": "Farfetch", "region": "Global", "url": "https://mostexpensivewatches.net/out/h_7300577755315/via/farfetch"}], "available": false}, {"id": "h_8086436544691", "title": "IWC IWC Big Pilot's Watch 43 Blue IW329304 (Pre-owned)", "brand": "IWC", "model": "IWC Big Pilot's Watch 43 Blue IW329304 (Pre-owned)", "reference": "—", "price_usd": 5300.0, "currency": "USD", "condition": "excellent", "box_papers": "full_set", "year": null, "case_material": "Stainless Steel", "case_size_mm": 43.0, "movement": "Automatic", "complications": [], "merchant_slug": "collective-horology", "merchant_name": "Collective Horology", "image_url": "https://cdn.shopify.com/s/files/1/0559/0623/8643/files/IMG_3391.jpg?v=1736883391", "detail_url": "https://mostexpensivewatches.net/listing/h_8086436544691", "buy_url": "https://mostexpensivewatches.net/out/h_8086436544691", "alt_buy_urls": [{"partner": "goldsmiths", "name": "Goldsmiths", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_8086436544691/via/goldsmiths"}, {"partner": "selfridges", "name": "Selfridges", "region": "UK", "url": "https://mostexpensivewatches.net/out/h_8086436544691/via/selfridges"}, {"partner": "farfetch", "name": "Farfetch", "region": "Global", "url": "https://mostexpensivewatches.net/out/h_8086436544691/via/farfetch"}], "available": false}], "auction_lots": [{"slug": "iwc-iw504101-2018", "brand": "IWC", "reference": "IW504101", "model": "Portuguese Sidérale Scafusia", "case_material": "Platinum", "hammer_usd": 215000, "year_sold": 2018, "venue": "Christie's Geneva", "lot_summary": "IWC's most complex astronomical watch, featuring a constant-force tourbillon, sidereal time, and a customized star chart on the caseback.", "source_url": "https://www.christies.com/en/lot/lot-6141234", "provenance": "ai_generated_grounded", "url": "https://mostexpensivewatches.net/auctions/iwc-iw504101-2018"}]}