Luanda is the most expensive city in the world for an expatriate professional migrant to live in as at October 2017, followed by Hong Kong and Singapore. The top ten most expensive cities in the world comprise one from Africa (Luanda (1)), three from Asia-Pacific (Hong Kong (2); Singapore (3); Tokyo (8)), four from Europe (Zurich (4); Geneva (5); Oslo(7); Monaco (10)), and two from America (Hamilton (6); Manhattan NY (9)).
https://www.xpatulator.com/cost-of-living-article/International-City-Cost-of-Living-for-Expatriate-Professional-Migrants_716.cfm