Building just 1 mile of border wall is very expensive.
It's said that it costs around $900 million dollars just for 1 mile of border wall.
That's a lot of money for something that is not worth even installing and a huge waste of taxpayer money that could be used in much better ways.
The cost goes for land, materials, and construction costs to pay the employees building the wall as well as maintaining the wall.
Then there has to be security at the border wall or the border wall could be scaled and climbed over.
However planes could just fly over the border wall as well.
Trump has wasted so much taxpayer money in building that stupid border wall that we do not need.