Meghan, who is expecting her first child with Prince Harry in April, will reportedly fly out of NYC Wednesday night.
King added: "I don't know what everybody got..."
"Secondly, I think, the sheer scale of the opulence of all this".
Meghan returned to the United Kingdom early on Thursday morning (21.02.19) after a £192,016 round trip, which saw her land back at Farnborough Airport, Hampshire.
"She was desperate for them all to get together and have some girly time away from the guys, so her pals arranged to all meet up in NY".
Elsewhere, she reportedly also forked out an extra US$86,316 for two royal protection officers, and a $625 harp player on her arrival - bringing the total cost of the getaway to more than half a million dollars. "It just speaks to who [Meghan] is".
It is believed that Amal and her family, excluding George, may have been heading to Teterboro private airport to meet up with Meghan to catch a flight back to London. "We wish you so much joy".
Abigail Spencer, a co-star on Meghan's former TV show "Suits", was among old friends in town to fete the upcoming birth.
"The celebrity world in which Meghan was submerged seems to be where all her friends are, and that can only spell disaster".
Other famous faces expected to be on the guest list includes Priyanka Chopra, Amal Clooney and Serena Williams.
Activities during the week included visiting the Met Breuer museum of modern and contemporary art and dinner at Ralph Lauren's restaurant the Polo Bar, according to media reports.
Kensington Palace has said the trip was "privately funded".