I've tried what I said for few times and found some really very cheap countries:

• Montenegro 0.04$
• Azerbaijan 0.06$
• Morocco 0.03$
• Tunisia 0.06$
• Algeria 0.02$
• Libya 0.04$
• Liberia 0.05$
• Haiti 0.05$

And here is another list with pricing for different countries;

http://www.rudibedy.com/blog/facebook-advertising-...

This is copied list found from Google search.

Hoping this was helping for FaceBook advertisers :)

Good luck my friends