Money, Togo, Ghana, Ivory Coast, Burkina Faso
All of French West Africa shares a common currency, the CFA, tied at 50:1 to the French Franc. In Paris you can convert unlimited amounts of Francs to CFA and back, thus giving these countries a hard currency, and French colonials a place where they can still do business as always.
The Anglophone countries (Nigeria, Ghana, The Gambia) all have their own currencies, with a corresponding rate of inflation, but (it seems) very serviceable.