The price tag sounds impressive at first but note that most of it never leaves american hands. Instead it is paid to contractors in key congressional districts.
While that might be true, that's kind of saying that if I go around breaking windows, I'm helping the economy as people are going to go out and spend money to buy new windows. Our society produces a limited amount of goods and services, and any allocation to one project means we have a little bit less for everything else. Whether the beneficiary is American or not isn't really relevant as it doesn't change the end result that everyone else has to tighten their belts to make room for the war.