FILING expenses is one of Baobab's least favourite things to do, never more so than after a trip to Angola. It is painful to explain to The Economist bosses that Luanda, the capital, really is that expensive. A by no means luxurious hotel room costs $400, a non-alcoholic drink in the lobby $10 ($2 in a supermarket). The underwhelming hotel buffet will set you back $75 and a pizza on a street corner $25.

A regular taxi ride easily adds up to $50, especially since the taxi company (the only one in town) starts the meter as soon as the car leaves the depot. There are no cruising cabs. For a driver with a decent car I paid $350 per day (for two days only, then I walked everywhere in 35°C heat and 100% humidity). An apartment costs $10,000-$15,000 to rent per month or at least a million dollars to buy. Labourers get paid $50 per month. That tells you a lot about the gap between rich and poor. Angola has one of the worst Gini coefficients in the world.

For several years Luanda has been the most expensive city in the world. That is not primarily a consequence of the influx of oil money, although there is a lot of it about since Angola is sub-Saharan Africa's second biggest producer. The crazy prices were initially the result of limited supply during and shortly after the civil war that ended in 2002. When peace became permanent, trade routes opened up again and new companies tried to enter the market.

But insiders had come to like the wildly above-average profits they were making and so made sure the trade barriers stayed in place. In Luanda an avocado can cost $5, while in the countryside you get a hundred avocados for $10. To get fruit to town, lorry drivers and merchants have to negotiate a mesmerising obstacle course of bribe-seeking officials, guards, thugs, policemen and soldiers.

The supermarket Casa Dos Frescos sold a melon for $100 shortly before Christmas to an irate Frenchman. He tried to sue the retailer for profiteering in a local court last month and presented a picture of the rather ordinary melon plus the receipt. The judge threw out the case for lack of evidence—the original melon. The Frenchman had eaten it.