Overall African countries are some of the poorest and least developed in the world, with relatively low local cost of living expenses; however the cost of importing and transporting the international standard of goods that expatriates expect to purchase in the cities in this region makes it extremely expensive to maintain the lifestyle that they are used to.
Despite the fact that the Angolan New Kwanza (AOA) is approximately 32% weaker against the US Dollar compared to a year ago, extremely costly safe expatriate accommodation, imported produce and international private schooling has kept Luanda as most expensive city to live in the African region.
Maseru in Lesotho is the cheapest African city. Lesotho has long been one of the poorest countries in the world. The economy of Lesotho’s economy is based on diamonds and water sold to South Africa, manufacturing, agriculture, livestock, and to some extent the earnings of labourers employed in South Africa.
http://www.xpatulator.com/cost-of-living-article/Africa-Expat-Cost-of-Living-Comparison-Rankings-April-2016_666.cfm