Looking at recent immigration trends, I'd say this is probably true.
Either way, simply comparing one massive quantity of wasted money to a larger quantity of wasted money does not really make the smaller one go away. Whether Medicare wastes $200 billon dollars per year or not, does not make wasting an additional $18 billion on border protection a good deal. Especially where the protection/ enforcement you're talking about would cost much more than $18 billion dollars per year.
Besides, citing our spending on defense [see offense] is outrageous and probably a poor talking point for any fiscal conservative.
As long as the United States has an economic opportunity for them, they are going to come here legally or otherwise. If it is easier, more beneficial and at all practical for them to enter the United States legally they will do exactly that. Ellis island was a perfect example of a functioning immigration system, where we convinced millions of immigrants to take their boats to a clearly defined immigration hub.
Keep in mind that our Atlantic coast is much larger [and at the time harder to enforce] than our land borders.