Africa on the other hand from what I know is both poor and expensive at the same time

How did you get that impression? I can't conform that at all. Rent in rural areas and outside of city centers is very low. If they rent at all. Local tribes live on land that they own or get assigned to by the government and at least don't have to pay for. The rest is food and other necessities.

The issue with micro-loans is that you need infrastructure to track/enforce the re-payments. I don't see how it can be done without significant local support and it may even have some legal implications.