The finances of the nation do not permit the first family to take vacations wholly on the taxpayer's tab.
Just as any citizen employed in a private-market is taxed on the estimated value of fringe benefits provided by his employer, the unelected members of the first family have enjoyed lavish vacations world-wide. Since the first family has no function in our government, these costs can only be fringe benefits provided to the President by his employers-- the taxpaying public.
Social justice demands an IRS levy on fringe benefits provided to every federal employee, including the President of the United States. He, therefore, must include in income benefits provided to Sasha, Malia, and Michelle Obama-- as determined by the CBO.