Sure, let's add up the cost.

What is the cost of a human life? What is the cost of the welfare of children whose only crime is following their parents across a border?

I don't pose these questions to signal virtue, but to point out the absurdity of assigning something like a cost function to something as natural as wanting a better life for oneself or one's children.

It might very well be true that "uncontrolled" immigration has an impact on the livelihoods of poorer Americans. Does this really imply that we should hurt the former in favor of the latter instead of helping both?