Would this discount be possible without Uncle Sam financing it? EU has been mad about the subsidies allegedly paid to Boeing, but the half-price deal would also reduce Europeans' expenditure on aircraft (harming the Airbus industry, though).
Economy is a delicate art sometimes...
Think you will find that going to anybody with a substantial order then a big discount will happen anyway.
Try going to a Ford dealer and offering to buy 200 cars and see what price you can get.
US EXIM Bank will finance, just like they finance other capital purchases.
Most countries provide Export funding or guarantees schemes for their exporters.