Don't forget that Biden gave away billions of military equipment to the Taliban.  Estimates go as high as $85 billion.   Kinda dwarfs the $8 billion.  And now in the hands of millitants, troublemakers.  Unprecedented transfer of wealth and fire power to our adversaries.

Also recall that Biden, by stopping the wall construction, had to pay the contractors for the contract suspensions.  Estimated between $ 1.8 billion and $ 2 billion.   Reports indicate it might have been cheaper to complete the wall than with Biden's suspending those contracts. 

AND YET CONSTRUCTION IS NOW RESUMING -- go figure --the contract suspension money is thus down the drain.  What a waste.  What poor judgement.

And before that wall was built, there were needs to send military there to help defend the border. Bush, Obama and Trump have sent military to the border to assist. Thus a budgetary savings would occur from having the wall, less needs to deploy the military.   Appears a strong tie into military budgeting. 

Military budget benefits/savings from investing bucks in the wall. 

As well as the social benefits of avoiding the overcrowding of soup kitchens, and shelters from those excessive numbers of Biden's illegals -- several million let in by the Biden administration.  Illegal invasions matching or exceeding the size of some US towns.