Libreville , Capital au Gabon is fairly expensive.

Housing: Around 1000 USD/ ( 3or 4 Bedroom in nice and secure place)
Fuel: Around 2USD per liter
Transport: Most people buy they own Car
Public Transport: Negotiable with the Taxi Driver based on the distance and pick Hour
Entertainment: 100 USD a botthe of Whisky in a Night Club
Coke: 0.5 USD for 345cl ( bottle )
Clothing: Average of 30 USd for a pair of Jeans ( Price increase with Quality )
Shoe: 15 USD for a normal Shoe
Medical : Private hospital cost around 40 USD for a Visit/Consultation
Hospitalisation in Private Hospital is around 600 USD
Going to the local market make thinkgs a little bit cheaper.

Moving to the economic City ( Port-Gentil , a small Island ) is definitely costly.