Furthermore, what you've exampled is only the direct cost of deporting people, i.e. the logistics etc.
The wider economy would be massively impacted, not just from the loss of tax revenues at the federal and state level, but from the loss of workers. Farm workforce is c.40-50% illegal immigrants, and construction at least 15%. There's also the studies that have shown that for every 0.5 million immigrants no longer working, the US-born workers lose about 40-50k jobs.
Then, with c.4-5 million children born in the US to at least one illegal immigrant parent, the mass deportation could create c.4 million single-parent families. Single-parent families are thought to cost the economy 20k USD in net debt per annum, so this would create a burden of c.80 billion per year from the splitting up of families.
The economy might ultimately suffer by being c.5% below where it would otherwise be - which might not sound much, but equates to c.1.4 trillion per year. Now that is a cost worth understanding.