The price of retail gasoline could fall by half, to around $2 a gallon, within 30 days of passage of a law to limit speculation in energy-futures markets, four energy analysts told Congress on Monday. Testifying to the House Energy and Commerce Committee, Michael Masters of Masters Capital Management said that the price of oil would quickly drop closer to its marginal cost of around $65 to $75 a barrel, about half the current $135. MarketWatch