and more a matter of international tourism. If I was Mexican, I might plan on going to Texas, California, or New Mexico instead, since I run the risk of being hassled at every turn for my appearance and accent.

As for decreasing costs, that relies on a lot of factors. One, this doesn't actually remove the illegals from burdening the state. Even if they are arrested, they're using state finances in the legal system. Additionally, this law does not prevent them from using hospital resources. If they are in great enough need, many hospitals and doctors will still treat them, and may not turn them in (if they even get the opportunity). Yes, you might see a decrease of illegals showing up for basic health care like treatment for the flu and the like, but an illegal that shows up with a broken arm won't be turned away, and many health care professionals will err on the side of not turning in individuals in lieu of violating patient privacy (which has no bearing on citizenship).

There may be a slight decrease in illegal-related costs, but I don't think they'll end up outweighing the costs of actually enforcing this law. Unless, of course, it becomes one of those laws that isn't very regularly enforced, which kind of defies the point, doesn't it?