If you can live on a dollar a day it's very possible to "earn a living" with bitcoins through the various service on this forum.
I haven't explored most of the African countries but i think the average income there is around 100-150 dollar per month and if you are a good spammer then you could make a living while posting on here and would be an added bonus if you have any other skills to offer.
30$ living is obviously not possible unless you have some nice friends & family.