Da-yangyu, the first island ever to be put up for auction in China, sold for 20 million yuan ($3.15 million) on Friday.Ningbo Gaobao Investment, which deals in real estate and tourism development, won a three-way bidding war for the right to use the land for 50 years and build a luxury resort.\"I think 20 million yuan is a reasonable price,\" said Yang Weihua, general manager of Ningbo Gaobao. \"It has rich natural resources, especially in vegetation and seafood, and it\'s a great spot for sailing on the big, blue sea.\"She said her company will invest about 500 million yuan into the project, but declined to reveal more details.Dayangyu Island, which lies off the coast of Ningbo in Zhejiang province, covers 258,000 square meters - the size of 36 soccer fields - and was once an orchard and hunting site.It is among the first batch of 176 uninhabited islands made available to domestic and foreign developers by the State Oceanic Administration.\"Located between urban areas and scenic attractions, Dayangyu is one of the islands with relatively good resources,\" said Jin Tengyong at the Xiangshan county ocean and fisheries bureau, explaining the 15-million-yuan reserve price at auction.\"It\'s just 300 meters off the mainland, meaning the island is more suitable for reclamation if you take into account the cost of infrastructure, such as fresh water, electricity and roads.\"