$3B is pretty small on the large scale. Especially when you consider the cost of adding them later (while it may not be paid for up front by the government, costs of doing construction, like closures, do add to gov't costs)

According to some sensationalist stories I've read, it's only ~10X what we're spending to protect/transport President Trump on his weekend vacations.

What does this contribute to the conversation?

Context. Reasoning about government budget-size numbers is difficult for most people.

Someone said it's not a lot of money. Someone else said it was. I provided a relative reference. Not the most monumental - but my intention was to add perspective.

In normal human terms, yes, but 3B is only .08% of the federal budget.

Also, there is some economic gain from this activity...paying construction workers to install it, and whatever the end users decide to do with it. Is that gain > 3B? I don't know.