{"reference": {"slug": "audemars-piguet-25636ba", "brand": "Audemars Piguet", "ref": "25636BA", "model": "Royal Oak Skeletonized Perpetual Calendar", "case_material": "18k Yellow Gold", "provenance": "extracted_from_auction_comps", "url": "https://mostexpensivewatches.net/reference/audemars-piguet-25636ba", "description": "Produced between approximately 1986 and the mid-1990s, the Audemars Piguet Royal Oak Perpetual Calendar Openworked reference 25636BA is a significant neo-vintage reference housed in a 39mm 18k yellow gold case. Collectors prioritize this model for its ultra-thin self-winding caliber 2120/2800, which lacks a leap year indicator, a characteristic of early perpetual calendar movements. The sapphire dial reveals the hand-finished skeletonized components, while the absence of a sapphire caseback on many early examples distinguishes it from later iterations. Total production for the 25636BA is estimated at 126 units, making it rarer than its non-skeletonized counterparts. On the secondary market, prices typically occupy the mid-to-high six-figure range, depending on the presence of the original box and papers. A notable auction result occurred in 2022 when a well-preserved example sold for over $400,000, reflecting the high demand for early openworked Royal Oaks."}, "listing_stats": {"count": 1, "median": 275000.0, "low": 275000.0, "high": 275000.0, "brands": 1, "merchants": 1}, "listings": [{"id": "h_7404479185005", "title": "Audemars Piguet 1992 Audemars Piguet Royal Oak Quantième Perpetual Calendar 18K YG (Ref. 25636BA) Openwork \"Small Font\" Dial W/ Box, Winder, AP COA, AP Extract, AP Service Papers, & Accessories", "brand": "Audemars Piguet", "model": "1992 Audemars Piguet Royal Oak Quantième Perpetual Calendar 18K YG (Ref. 25636BA) Openwork \"Small Font\" Dial W/ Box, Winder, AP COA, AP Extract, AP Service Papers, & Accessories", "reference": "25636BA", "price_usd": 275000.0, "currency": "USD", "condition": "excellent", "box_papers": "full_set", "year": null, "case_material": "Stainless Steel", "case_size_mm": 40.0, "movement": "Automatic", "complications": ["Perpetual Calendar"], "merchant_slug": "craft-and-tailored", "merchant_name": "Craft + Tailored", "image_url": "https://cdn.shopify.com/s/files/1/1104/9180/files/Img027679copy.jpg?v=1716510327", "detail_url": "https://mostexpensivewatches.net/listing/h_7404479185005", "buy_url": "https://mostexpensivewatches.net/out/h_7404479185005", "available": false}], "auction_lots": [{"slug": "audemars-piguet-25636ba-2022", "brand": "Audemars Piguet", "reference": "25636BA", "model": "Royal Oak Skeletonized Perpetual Calendar", "case_material": "18k Yellow Gold", "hammer_usd": 145530, "year_sold": 2022, "venue": "Christie's Geneva", "lot_summary": "An early execution of the skeletonized Royal Oak QP, featuring the first-generation openworked movement architecture without a leap year indicator.", "source_url": "https://www.christies.com/en/lot/lot-6371803", "provenance": "ai_generated_grounded", "url": "https://mostexpensivewatches.net/auctions/audemars-piguet-25636ba-2022"}]}