I have put together somewhat of a spreadsheet for the budget minded overlanders on typical pricing of what to expect in each country. They may not be accurate, as they have all been pulled from a user contributed database. However the database does claim to have current and timely information. They are statistical averages for each country as a whole - prices may vary throughout the country but this is based on averages. I also left out some countries that are not typically crossed by overlanders.

Please, if you notice anything that looks odd or way off the mark, let me know.
I took the most logical costs such as meals at an inexpensive restaurant, a meal for 2 at a moderate restaurant, carton of 12 eggs (for camping cooking?), price of a 0.5L local draught beėr, gasoline per litre, and unfortunately I couldn't get a price of hostel/cheap hotel accommodation, but I threw in cost of renting a house in the city centre to give an idea of city expense.

Please keep in mind, I don't know how accurate the gasoline prices are on this website (Numbeo.com), so I also took prices from a secondary website which I will post at the bottom. Meal #2 is the 2 person meal at moderate restaurant.

WEST AFRICA - Price in Euro
Morocco: Meal = 2.74 // Meal = 13.70 // Eggs12 = 1.14 // Beer = 2.28 // Gas = 0.89 // Rent Pm CC = 306
Mauritania: Meal = 3.05 // Meal = 4.58 // Eggs12 = ??? // Beer = ??? // Gas = 1.10 // Rent Pm CC = 203
Senegal: Meal = 3.65 // Meal = 38.15 // Eggs12 = 1.78 // Beer = 2.29 // Gas = 1.32 // Rent Pm CC = 534
Gambia: Meal = 3.87 // Meal = 13.43 // Eggs12 = 1.84 // Beer = 1.34 // Gas = 1.19 // Rent Pm CC = 123
Guinea-Bissau: Meal = 8.25 // Meal = 26.00 // Eggs12 = 1.78 // Beer = 1.09 // Gas = 1.12 // Rent Pm CC = 365
Guinea: No information
Sierra Leone: No information
Liberia: Meal = 4.39 // Meal = 26.34 // Eggs12 = 1.76 // Beer = 1.76 // Gas = 1.62 // Rent Pm CC = 1229?
Mali: Meal = 3.59 // Meal = 29.87 // Eggs12 = 1.76 // Beer = 1.80 // Gas = 1.25 // Rent Pm CC = 207
Ivory Coast: Meal = 7.25 // Meal = 38.83 // Eggs12 = 2.14 // Beer = 3.51 // Gas = 0.96 // Rent Pm CC = 559
Ghana: Meal = 6.15 // Meal = 43.90 // Eggs12 = 2.02 // Beer = 1.32 // Gas = 0.89 // Rent Pm CC = 993
Togo: Meal = 3.05 // Meal = 12.21 // Eggs12 = ?.?? // Beer = 0.92 // Gas = 1.22 // Rent Pm CC = 76
Benin: No information
Burkina Faso: Meal = 6.10 // Meal = 22.89 // Eggs12 = 1.31 // Beer = 1.53 // Gas = 1.01 // Rent Pm CC = 106
Niger: Meal = 4.20 // Meal = 20.60 // Eggs12 = 3.07 // Beer = 1.53 // Gas = 0.79 // Rent Pm CC = 686
Nigeria: Meal = 2.06 // Meal = 25.34 // Eggs12 = 1.56 // Beer = 1.10 // Gas = 0.42 // Rent Pm CC = 500
Cameroon: Meal = 3.28 // Meal = 21.95 // Eggs12 = 1.62 // Beer = 0.92 // Gas = 0.97 // Rent Pm CC = 269
Equatorial Guinea: Meal = ??? // Meal = 64.00 // Eggs12 = 1.86 // Beer = 1.14 // Gas = 0.72// Rent Pm CC = 610
Congo: Meal = 14.0 // Meal = 43.76 // Eggs12 = 3.18 // Beer = 2.19 // Gas = 1.45 // Rent Pm CC = 1042
Angola: Meal = 17.5 // Meal = 59.27 // Eggs12 = 3.95 // Beer = 1.98 // Gas = 0.86 // Rent Pm CC = 2985
Namibia: Meal = 5.89 // Meal = 23.57 // Eggs12 = 1.57 // Beer = 0.94 // Gas = 0.67 // Rent Pm CC = 386
South Africa: Meal = 5.89 // Meal = 23.57 // Eggs12 = 1.31 // Beer = 1.30 // Gas = 0.76 // Rent Pm CC = 312

Taking the average of a few, I picked;
Cheapest Meal: Morocco, Nigeria, Mauritania, Togo, Cameroon, Senegal
Cheapest Gasoline: Nigeria, Namibia, Liberia, Togo, South Africa, Niger

EAST COAST/CENTRAL
Botswana: Meal = 4.16 // Meal = 24.10 // Eggs12 = 1.86 // Beer = 1.79 // Gas = 0.69 // Rent Pm CC = 319
Zambia: Meal = 5.18 // Meal = 23.20 // Eggs12 = 1.23 // Beer = 1.18// Gas = 0.88 // Rent Pm CC = 282
Zimbabwe: Meal = 7.63 // Meal = 26.34 // Eggs12 = 1.85 // Beer = 1.01 // Gas = 1.19 // Rent Pm CC = 325
Mozambique: Meal = 6.09 // Meal = 24.38 // Eggs12 = 1.13 // Beer = 0.98 // Gas = 0.78 // Rent Pm CC = 521
Malawi: Meal = 3.80 // Meal = 30.02 // Eggs12 = 1.59 // Beer = 1.10 // Gas = 1.68 // Rent Pm CC = 335
Tanzania: Meal = 4.07 // Meal = 24.25 // Eggs12 = 2.08 // Beer = 1.12 // Gas = 0.89 // Rent Pm CC = 539
Burundi: Meal = 5.03 // Meal = 18.26 // Eggs12 = 2.08 // Beer = 1.76 // Gas = 1.25 // Rent Pm CC = 380
Rwanda: Meal = 2.26 // Meal = 22.56 // Eggs12 = 1.40 // Beer = 0.90 // Gas = 1.03 // Rent Pm CC = 386
Uganda: Meal = 1.58 // Meal = 10.53 // Eggs12 = 1.04 // Beer = 0.92 // Gas = 0.96 // Rent Pm CC = 155
Kenya: Meal = 2.62 // Meal = 21.84 // Eggs12 = 1.38 // Beer = 1.75 // Gas = 0.84 // Rent Pm CC = 273
Ethiopia: Meal = 2.96 // Meal = 17.56 // Eggs12 = 1.38 // Beer = 0.88 // Gas = 0.85 // Rent Pm CC = 231
Djibouti: Meal = 7.43 // Meal = 34.34 // Eggs12 = 2.68 // Beer = 4.96 // Gas = 1.24 // Rent Pm CC = ???
Sudan: Meal = 3.51 // Meal = 13.93 // Eggs12 = 1.61 // Beer = ?.?? // Gas = 0.63 // Rent Pm CC = 437
Egypt: Meal = 3.46 // Meal = 19.77 // Eggs12 = 1.11 // Beer = 1.19 // Gas = 0.26 // Rent Pm CC = 220

Other Gas Prices
Real gas prices

West Coast*************
Morocco = 1.00
Mauritania = 1.33
Senegal = 1.22
Gambia = 1.29
Guinea-bissau =
Guinea = 1.21
Sierra-Leone = 0.97
Liberia = 0.76
Mali = 1.19
Ivory Coast = 1.00
Ghana = 0.92
Togo = 0.83
Burkina Faso = 1.29
Benin =
Niger = 0.93
Nigeria = 0.45
Cameroon = 1.11
Congo = 0.95
Angola = 1.04
Namibia = 0.69
South Africa = 0.89

East Coast*************
Botswana = 0.72
Zambia = 0.96
Zimbabwe = 1.27
Mozambique = 0.98
Malawi = 1.21
Tanzania = 0.81
Burundi = 1.24
Rwanda = 1.15
Uganda = 1.00
Kenya = 0.84
Ethiopia = 0.80
Djibouti =
Sudan = 0.80
Egypt = 0.73

It is a bit disappointing to have such conflicting information in the gas prices, in brings into question the accuracy of everything else. On checking with several European countries, most of the living costs were fairly similar. I don't expect it to be dead on accurate, but more or less a "Ball park" estimate.

I do this as I have no idea of the costs, and being on a tight budget I am trying to figure the places I can spend a longer duration, and the places I probably can't afford to. Of course, cost is not the only factor of time spent in a country, however it is all part of preparation, and to not be totally shocked on arrival.... much like how I was with Israel (what a rip-off)

If you have any more accurate estimates or averages, please comment below so I can update the list. Please share your information!