There are many ways of determining the prices of the product you're selling. One common factor is to set a profit margin of not less than 20 percent of the cost of the products. There are items that are fast selling because it's considered a basic commodity, in which case one will have to observe the. surrounding community because these are also regulated products and has a price ceiling. It's of an advantage if you're the sole maker of the product because you can dictate your price as long as it's competitive with some. similar products.