We actually used a 'tourist' taxi on that day; sometimes we would use a 'bush' taxi to get around.
Bush taxis are a real experience; they are ex-tourist taxis i.e. too poor to continue (and no tourist taxi would ever pass an MOT here) - so passengers get involved with helping to push/fix them!
Cheap though, you would expect to pay about 30 Dalasi (60 pence) per hour of travel.........