They aren't. Nor is toothpaste like $5. A lot of the prices for things listed are not even close and make no sense. The higher COL things here are taxes, gas, utilities and insurance.
The most recent list I saw (Economist?) had Juba, N'Djamena and Luanda in the top ten so clearly people are using different metrics here!
I think that might've been a list for expats. At least a list I saw last year with Luanda on it was for expats. I have a friend here from Angola and when he told me that Luanda was on some list about being really expensive to live in I didn't believe him and had to look it up for myself!