A lot depends on what kind of Sacco it is.There are national-wide Saccos and also those based in Nairobi only.The national wide ones will hardly ever give much because of branch running expenses and education seminars while the small Nairobi based ones give much more since they are investing in real estate. The rent from such real estate is income to the Sacco and the only way of distributing to members is through dividend.
With SASRA now, they will have to form a separate investment company since real estate is not a core business of any Sacco.Then expenses will start eating into income.
That said,I would be very cautious of one that has been offering 15% pa.I would be happy....but I would also want to know who they lend at 20%!Or is it that they have rental income?
You have saved so much there....please find out HOW they make the money to give out such dividend.
Formally employed people often live their employers' dream & forget about their own.