Bleah. Minor exaggeration. The point you may or may not get--I can't tell--is that there are two separate questions here. First, what should we do about immigration? Answer: encourage it. Second: what should we do about flagrant lawbreaking? Answer: punish it severely.
Incarceration? Well, we know how expensive that is -- even if the government decided to use the incarcerated illegals in chain gangs that just happened to be part of construction crews and produce picking crews. And again, Mexico would protest. It could even decide to divert oil to China (nice of us to have built the Panama Canal).
To date, the cheapest solution is repatriation, usually by bus.
The one form of punishment that actually generates income is to fine the businesses that knowingly use illegal labor. But as already discussed on this thread, it's all a game.