You get what you pay for.
Boeing (and I presume Airbus) has long been known for offering substantial discounts from the sticker price, airline A pays more than airline B for the exact same aircraft regularly. It's a prestige thing for Boeing as much as anything, had Trump encouraged Airbus to enter the flying forehead into the competition in a serious manner, Boeing would have scrambled. Don't think for a minute he wouldn't have encouraged them to, if nothing else he's shown he not a slave to orthodoxy, and having the President on a Boeing is a prestige thing only.