C-17s cost $25,000 per flight hour to run. Even a short south Texas to Guatemala round trip will be 5 hours per plane. A quarter million dollars to move 160 people, not including the cost of the logistical trail. Mexico saved a lot of spending denying flight #3 https://www.nbcnews.com/politics/immigration/mexico-refuses-accept-us-deportation-flight-rcna189182