Retailman,
That about boils down to mama-shop or chup huay tiam kind of business, isn't it?...
Thing is, there's easy entry to be reckon with, others will see the easy model & latch on (to your neighborhood)... soon you will be in the middle of a price war, etc., won't you?
Besides, although it would seem a simple model to take. From what I can observe from my friend's parents' shop, it has a wide range of issues to handle: distributor for goods, how to compete with the
NTUC/Giant/Carrefour, the 7 days week, customer-loyalty, shop-lifting, vandalism, etc, etc...
Ah well, theorists like me, always have a criticism for any stuff... Perhaps it is a risk thing to take (these competitors and all)... I guess I am a bit chicken-hearted about participating in a retail business.