Cost of goods sold or cost of sales is the accounting term for the price companies pay for manufacturing their products - materials, labors, factory costs, etc. If you resell products, the cost is what you pay to your suppliers for them plus storage, shipping, etc.
— Profit margin or just margin is an accounting term, showing what percentage of the retail price your profit is. It is the ratio between the profit and the retail price. The profit margin formula is: Margin = (retail price - cost of goods) / retail price
— Overhead costs are all the costs for running a business apart from the strictly product-related ones, e.g. cost of goods sold. Overhead costs are utilities, office and storage rent, marketing, non-manufacturing labor, etc. In ecommerce, the most important