Tokyo is most expensive city for expatriates and Oslo the most expensive city in Europe. - According to the latest ECA International survey into the cost of living for expatriates, Tokyo became the most expensive city in the world in 2010. Oslo is the most expensive city in Europe and stole first place from Copenhagen (3rd). Stavanger, also in Norway, is the second most expensive city in Europe, whereas Chisinau, the Moldavian capital, is the least expensive, followed by Minsk and Kiev....