Ray,
Though I haven't worked or lived overseas, I did some calculating a while back on moving with my wife to another country and starting a job. One of the main things I don't see you considering is your current family/network of friends. If you currently have family or friends that you see and/or rely on for help with the kid, visiting, just hanging out with, that is pretty much going to all end. My guess is that the move would be hardest on your wife if she's to be stuck at home in a new country and very few if any friends that she can visit with close by. To me, that would be the biggest thing to consider. If she's not happy 3-6 months down the road, do you both have the fortitude to stick it out until the year is done?
Rick