Cost of living is pretty low in Ethiopia IF you're a native.
You're taking the cost of living where you are, which is likely 1st World, and applying that to ADD and ET's salary. Guarantee you the locals can get by on a much much less.
I've lived in DRC for 3.5 years. Not that I'd want to, but for $1000/month I could have a pretty decent life, including housing, food, etc.....