Where are all the books written in French? In the countries that speak French of course!

Does anyone know where I can order inexpensive (~$10) books that are written in French? I'm looking for specific websites. I wanted to buy some reference books and novels to take to Haiti, but am having difficulty. I found some on Amazon, but SpSq's favorite book The Eight (Le Huit) is $40! And I found a site that imports novels from France, and they are expensive. I'll try the used books sites again, but seems like they are all >$20. PS - I'm reading The Fire and it is great! And I'm home sick so it's a good day to look up things on-line. HA - followup - there's a bookstore in Haiti's capital!