By taxi
The small green taxi cabs should cost no more than 200CFA per person during the day, but be prepared to share the cab with as many people as can be crammed in. Cabbies may attempt to charge foreigners far more. If you have a lot of baggage, expect to pay more indeed.
Prices go up at night somewhat, but you should never pay more than 500CFA, which is negotiable if you have a lot of people in your group to share the cab.
Be aware, that if you are loaded up with bags, in the middle of the night, and wanting to get to a far away destination, cabbies will try to milk you for as much as possible.
There are also white taxi cabs that are much more expensive, but much more reliable, and you don't have to share seating with others going to different destinations.