Some of this differential is because of the current dollar to French franc exchange rate. Salaries vary greatly from school to school. In my experience, this is based not on the cost of living in these areas but on the availability of teachers. However, as I've done this for 20 years, I obviously feel that the positive outweighs the negative. The school population is really exciting.
Many students are true global nomad.
They've lived all across the world. In my current school, the 850 students from grades pre-K through the 13th year of the International Baccalaureate program represent approximately 45 nationalities. Roughly 50 percent of them hold U.S. passports. Living in a different culture expands horizons and empathy levels. It's not always easy, but it's rarely boring.