I guess from an emotional point of view this comparison would serve some purpose. However the logic is flawed.
One does not calculate the expense of A based on the the expense of B unless there is a relationship between the two.
How does the money "spent" on illegal aliens in any way influence the costs of the Invasion?
This makes about as much sense as those people who claim that the Invasion is not that bad as more military died in one battle in WW-II than in the Invasion.
Sooooo?
One should not confuse emotions with logic.