U.S. President-elect Donald Trump said on Thursday that because of the high cost of Lockheed Martin Corp's F-35 fighter, he had asked Boeing Co to offer a price for a "comparable F-18 Super Hornet." "Based on the tremendous cost and cost overruns of the Lockheed Martin F-35, I have asked Boeing to price-out a comparable F-18 Super Hornet!," Trump wrote on Twitter....