{"reference": {"slug": "audemars-piguet-25829tr", "brand": "Audemars Piguet", "ref": "25829TR", "model": "Royal Oak Perpetual Calendar Openworked", "case_material": "Tantalum and 18k Pink Gold", "provenance": "extracted_from_auction_comps", "url": "https://mostexpensivewatches.net/reference/audemars-piguet-25829tr", "description": "The Audemars Piguet Royal Oak Perpetual Calendar Openworked reference 25829TR was produced from the late 1990s through the mid-2010s. This reference is distinguished by its bi-metal construction, pairing a tantalum case and outer bracelet links with 18k pink gold bezels and center links. Collectors prioritize this model for its skeletonized caliber 2120/2802, an ultra-thin automatic movement visible through the sapphire dial and exhibition caseback. The use of tantalum, a dense and difficult-to-machine refractory metal, makes this variant significantly rarer than standard steel or gold iterations. Current secondary market valuations typically fall within the $250,000 to $400,000 range depending on condition and provenance. Production records suggest that fewer than 100 units of the 25829TR were manufactured, and a notable example sold at a Phillips auction in 2021 for approximately 302,000 CHF, confirming its status as a low-volume collector piece."}, "listing_stats": {"count": 0, "median": 0, "low": 0, "high": 0}, "listings": [], "auction_lots": [{"slug": "audemars-piguet-25829tr-oo-0944tr-01-2024", "brand": "Audemars Piguet", "reference": "25829TR.OO.0944TR.01", "model": "Royal Oak Perpetual Calendar Openworked", "case_material": "Tantalum and 18k Pink Gold", "hammer_usd": 315000, "year_sold": 2024, "venue": "Sotheby's New York", "lot_summary": "A rare combination of tantalum and pink gold, limited to just 16 pieces, featuring a skeletonized perpetual calendar movement.", "source_url": "https://www.sothebys.com/en/articles/the-audemars-piguet-royal-oak-rose-gold-revisiting-the-most-expensive-models-sold-at-sothebys", "provenance": "ai_generated_grounded", "url": "https://mostexpensivewatches.net/auctions/audemars-piguet-25829tr-oo-0944tr-01-2024"}]}