I saw a video about the wall Trump's supposedly going to build, and I did a little mental maths regarding how much it would cost to run.
The average security guard in America earns $14 per hour, rounding up (
source). Now obviously, it's no good just having them there 9 to 5 Monday to Friday, you're going to need them there 24/7. So that's $
336 for 24 hours. My godfather worked in the security business for most of his working life, and he said you'd want at least 5 guards per mile of wall. The wall would be around 2000 miles long, so that would be roughly 10,000 guards. So that would cost $
3,360,000 per day, or to put it another way $
1,226,400,000 per year. Hell even if you made huge cutbacks and went as low as 2 guards per mile it would still cost
$490,560,000 per year. And that's just in wages. That's before you've bought their clothes, food, water, weapons, ammunition, cameras and other equipment. AND this is assuming you're using the basic average joe security guards. The more highly trained ones will cost you much more. And since Mexico will NOT pay for the wall (
source), all that money would be coming straight out of your taxes.
Oh and that doesn't include the cost of maintaining the wall either.