A friend of mine did this kind of work. He worked for KBR as some kind of contractor (in the green zone, out of the field). He said he grossed 216k in one year, 80k tax free. He also said that because he was always in the same location and working 12/hrs day, meals free, room free, he spent <i>very</i> little of what he earned. This was 2007, and he was ex-military, so mmv.