Angola vies with Nigeria for the title of Africa's largest producer of crude. Oil money has driven an economic boom that saw GDP grow an average 11.2 percent a year in the decade to 2008.

But the country was left with next to no industry after its 27-year civil war ended in 2002, forcing it to import most of its consumer goods from Europe, China and South America.

Oil wealth has combined with an influx of foreign currency and congestion at the overwhelmed port in the capital, Luanda, to send prices soaring. The inflation rate was 14.5 percent in 2010.

Astronomical prices in the local kwanza greet customers every time they visit shops. Commuters are sometimes forced to jog to work when Luanda's ramshackle public mini-bus taxis suddenly increase fares.

Rising fuel costs since a reduction in subsidies are often blamed for the galloping prices. Angola pumps 1.9 million barrels of oil a day but imports 50 percent of its refined fuel, making the finished product expensive despite the country's large output of crude.

About 86 percent of Angola's urban population lives in slums, with only intermittent water and electricity. In Luanda, luxury ocean-side villas where expatriates and rich locals live tell a tale of a city battling with a gaping wealth divide.

Oil has attracted an influx of foreign companies that bring with them their own staff who live on high salaries and allowances.

But the pinch of high prices is also felt by top-earning expatriates.

Luanda was ranked the most expensive city in the world for expatriates in a 2010 study by the Mercer consulting firm, ahead of Paris, London and Tokyo.

Nadine, a Lebanese Expat who lives in Alvalade, an affluent suburb on the outskirts of the city, pays $10,000 (7,300 euros) a month to rent a three-bedroom house.

She says she spends about $5,000 a month on groceries to feed her family of four, not including eating out.