"Tariffs provide additional revenue for governments and domestic producers at the expense of consumers and foreign producers."
So when it costs more to purchase goods being imported from other countries, what happens?
"Governments may impose tariffs to raise revenue or to protect domestic industries from foreign competition, since consumers will generally purchase foreign-produced goods when they are cheaper."
I don't think you realize what kind of effects a tariff actually have.
Now, I'm no expert on economics but thankfully there are tons of resources online that allow us to see what the actual result of such a tariff would be. If we look at
http://faculty.washington.edu/danby/bls324/trade/tariff.html and scroll down to "A Tariff in a Large Country" (I'm sure we can all agree that the US is a large country) we see this infographic:
Basically this diagram shows how supply/demand (Supply is blue, demand is red) affects money coming in/being lost through tariffs. It shows that US consumers would be paying for a massive
half of the total cost of the tariff, with Mexico paying the other half.
This diagram also has other kinds of consequences, one of which being that there is indeed an "Ideal" tariff amount to maximize profit to the US. I have no idea how the exact supply/demand and tariff percentage would affect profit in this specific case, so I can't say for sure, but chances are that such a large tariff would be well, well beyond what is the ideal. Tariffs are usually in the range of single-digit percentages, not half to 100%, such a substantial tariff would definitely not be ideal and the vast majority of the area would be outside the profit rectangle shown in the picture, and end up in just lost money entirely. There's only a limited amount of money to be made from Tariffs.
It would also quite drastically affect the Mexican economy and the country as a whole. The US makes up the bulk of Mexico's exports, 3/4ths of it in total. Such a large tariff would drastically lower that number, which means less money for the country as a whole. US exports alone make up almost a quarter of Mexico's total GDP. Imagine the entire country suddenly loosing over 10% of its money due to a massive tariff. The economy would not like that at all.
Then on top of that you have the fact that such a huge tariff would be a blatant violation of WTO rules, Mexico would be more than in the right to take action against this and be eligible to, in return, also Tariff US imports for an equivalent value. This wouldn't even make a dent in the total US GDP, but it would make up for a significant portion of the half of the cost that Mexico lost.
So in the end, no, they wouldn't end up paying that much at all. Most of the cost would be put onto US citizens and Mexico would get back a large chunk of what they lost by literally taking it back from the US.
"Mexico must pay for the wall and, until they do, the United States will, among other things: impound all remittance payments derived from illegal wages; increase fees on all temporary visas issued to Mexican CEOs and diplomats (and if necessary cancel them); increase fees on all border crossing cards – of which we issue about 1 million to Mexican nationals each year (a major source of visa overstays); increase fees on all NAFTA worker visas from Mexico (another major source of overstays); and increase fees at ports of entry to the United States from Mexico [Tariffs and foreign aid cuts are also options]."
All of these would be small-game kinda stuff. It would be a drop in the bucket compared to the total cost.