28 Steem = 4979.431 Nigerian Naira (NGN)
28 Steem = 12.001848 US Dollar (USD)

When I used to travel, I used to look up the prices of Coca Cola. It is water and sugar and a little flavouring but it used to give a good comparison for prices.

This tells me that you are paying twice the amount that you should be for Coca Cola.

When I travelled to Ukraine, I learned about a drink they have there called Kvass. The most popular recipe uses Rye Bread in water, sugar and yeast. Its taste is a distant cousin to Coca Cola. It ferments slightly before bottling so it becomes fizzy (carbonated). Alternative recipes include fruit and one liver healthy drink is made from beets.

Perhaps people in your neighbourhood might like the taste of Kvass and it is something that you could make or perhaps get a neighbour to make for you to sell in your store.