Anyone know the answer

A vintage Omega Searnaster watch is up for sale. It will be sold via an auchon. Assurne there are four bidders, and that all care only about their own private value of owning the watch (they do not plan to ever sell it in the future. Their valuations are: $300, $500, $800, $1200. If the auctioneer uses a sealedbid, secondprice auchon: What will be the Winning bid? What will be the net bavoti to the Winner