You make the mistake the press always trots out. The extra cost of naval deployment is near $0.
The ships are always manned and are either at sea or temporarily in port. The fact that those at sea are deployed together in the southern Caribbean is not extra cost.
Whining about weapons use is just ridiculous.
The plans for engaging the cartels in Mexico or Venezuela are secret but certainly exist
Crews gotta practice...
They can shoot drug running boats out of the water or pratice on the range..
But you are correct, they will still be using the equiptment and weapons