The Telegraph reports his income as $1 a month.
Why does this article say $1 a day?
Here is another:
Barack Obama’s homeless half-brother found living in Kenya shack, earning less than $1 a day
http://www.mailonsunday.co.uk/news/article-1047399/Barack-Obamas-homeless-half-brother-living-Kenya-shack-earning-1-day.html