RE: Buying food or cooking at home, which is a most frugal means?

Exactly...

I heard that a place of rice and chicken here cost about 1500naira/$1.89 and that's a meal for just one person.

I will actually drop by within the week to see the quantity of such meals.
But I totally agree that it is cheaper to cook at home.. Just that it may not be too convenient if we have too many schedule.