If you've got a waterfront house and estate so grand that it's a good idea to build a lighthouse just to make sure no one crashes into it, you've probably got a little bit of money. You've got personal lighthouse money. Such is the case with the 5-BR, 4-bath, 9,969 residence at 8415 SW Soper Road on Vashon Island that just listed for a whopping $18 million. Owned by Trojan Lithograph Corporation & Corrugated Synergies International Chairman Hans Koch and wife Cynthia, the 1999-built residence rests on almost 24 acres of land with over 1,000 feet of beachfront. Hence the lighthouse.