Audemars Piguet 25820SP (Pre-owned - Good) — USD 145,466 on eBay

The Reference 25820SP represents Audemars Piguet's Royal Oak Offshore Chronograph in a mixed-metal configuration. This 42mm chronograph combines stainless steel and platinum case construction, distinguishing it from standard steel variants within the Offshore chronograph series. Production spanned from 2000 to 2008. The watch features a stainless steel and platinum case measuring 42mm in diameter with a fixed octagonal bezel. A black dial sits beneath sapphire crystal, while the automatic Caliber 2226/2840 movement provides chronograph functionality with a 50-hour power reserve. Water resistance is rated to 100 meters, and the watch is fitted with a rubber strap. This reference appeals to collectors seeking Royal Oak Offshore chronographs with premium mixed-metal construction. The platinum and steel combination positions it above standard steel models while maintaining the series' 42mm case size and automatic movement architecture. The eight-year production window and specific material combination define its place within the broader Offshore chronograph lineup.