MMA star Conor McGregor is well known for his knock-out wins, but he also maintains a knock-out watch collection. McGregor’s collection has several Rolex models (Oyster perpetual day date, Oyster perpetual yacht master II, Day date 40, Sky-Dweller, Daytona), several Patek Philippe models (Nautilus, Calatrava skeleton edition, limited edition Hulk), several Audemars Piguet models (Royal Oak Offshore, special edition Royal Oak Chronograph) and a selection of other premium brand brands (Breguet, Jacob & Co., Franck Muller). This watch collection easily comes to over one million euro in the so-called grey market, where watch aficionados buy and sell pre-owned watches at…