Now that the Clinton administration is preparing to build a Star Wars missile shield, some entrepreneurs are sniffing at the scent of new money (beyond the $60 billion spent since President Reagan unveiled the plan 16 years ago). Out in the Pacific, officials of the Republic of the Marshall Islands are hinting that they expect the Pentagon to pay more for its use of the Kwajalein atoll. Kwajalein’s isolation and its shallow, 900-square-mile lagoon have made it an ideal bull’s-eye for U.S. missile tests for decades. The Pentagon has access to “Kwaj” through 2001, with a renewal option to 2016. As part of the deal, the islands get American aid. But they want more. The islanders say the $10 million they pocket each year isn’t enough. Instead, they want “fair market value” for the use of their island. Given the Pentagon’s peculiar use for the atoll, it may be hard to set such a price. But it’s a safe bet, like the missile interceptors to be tested there, that it’s headed up. Way up.