The world's most and least expensive cities plus the most expensive extreme hardship postings

The world's most and least expensive cities plus the most expensive extreme hardship postings: "Luanda in Angola, Libreville in Gabon and N'Djamena in Chad are the most expensive extreme hardship locations in the world and thanks to the marketplace volatility which results from local inflation, political instability, currency fluctuations and natural disasters, Tokyo has consolidated its title as the most expensive city in the world in which to live."