Who is paying for "The Wall"

You are silly. 
Whadja think, Mexico? HAHHAHAHHA
I would also like to point out MODERN THECHNOLOGY as a cost effective alternative.
A couple of quansit huts and folks with drones, motion sensors...ect ect.

The dishonest media does not report that any money spent on building the Great Wall (for sake of speed), will be paid back by Mexico later!

— Donald J. Trump (@realDonaldTrump) January 6, 2017