One would think 1.5 billion would be sufficient but this is the government and we're talking about. I am not sure 1.5 would cover the cost of paper for all the reports and studies they would waste more time on. Let's just all be honest and admit neither of the establishment parties want to do much about illegal immigrants. It's too advantagous politically on the never ending campaign trail.
Environmental impact studies alone will cost that much. At least. Gotta make sure there's not some endangered desert mouse or something. The wall might mess with their mating rituals. I can picture/hear Cryin' Chuck Schumer now: "What is happening to the 3-toed Arizona sand mouse is a national tragedy and must be stopped immediately".
https://morningconsult.com/2018/12/...evisits-low-as-government-agencies-shut-down/ Trump’s Popularity Revisits Low as Government Agencies Shut Down Plurality of voters say president mostly to blame for funding lapse amid fight over border wall