With regards to the Flying Bribe 747 ... It's clear that the "gift" is to FFOTUS and thence to his "library" is a personal gift and not to the United States.
So... Who is going to pay the income tax (and perhaps import duty/tariff) on that airplane? It should be ol' FFOTUS himself.
And about maintenance and expenses - again those should come out of FFOTUS' own pocket, not from taxpayers.