Considering the Superfund cleanup that would have to be done on the entire country of Mexico to make it inhabitable under current EPA regs, a 700 mile wall will be much cheaper. Let them keep their crapheap country and clean it up (environmentally and politically) themselves.
I'm pretty unconcerned about the cost of the wall. 2-3 billion is a bargain at any price. However, I want auditors attached to the checks, but like in Katrina, I'm sure they won't be. Whatever, as long as we get the wall.