I made it up. The price really doesn't matter. It could be $3 a head or $30. Until it becomes important to the voter it will never be important to the politician. (I don't agree with this I'm simply saying that this is the facts of life.)
As long as the average citizen views this as a non-problem. As long as Presidents grant clemency to illegals... and as long as farmers and industry hire illegals... and as long as there is a profit to be made by cheap labor we will never see INS or the Border Patrol with the power they need to enforce our borders.
Yes there is a legal way to enter this country but sealing the border to illegal Mexicans is a political time bomb for any politician elected in a border state. Until 9/11 illegal entry was never a major problem for either political party.