But you also want to count where the $600M go to. Yes, US taxpayers pay for it eventually, but they pay it to some other taxpayers (assuming the developers also

But you also want to count where the $600M go to. Yes, US taxpayers pay for it eventually, but they pay it to some other taxpayers (assuming the developers also US-based). So the money get back to US economy in the end. Granted it's still bad for the economy, but just counting money is not enough. E.g. spending huge money on Hoover dam and Golden Gate bridge was good for the economy at the time.