Below is a breakdown of costs on a unit level to determine your gross profit margin:  COG’s: These are your cost to product the product Freight: Costs to ship the product to Amazon FBA FBA: Fulfilmment costs by amazon. Cost to handle and ship your product to the customer, depends on weight and size tiers. Use calculator below to work out Referral fee: the cost per unit to sell on Amazon’s platform depends on price and product category, this is usually between 10 and 15% Returns: depends on product category, but budget for about 2% of sales price ACOS: Amazon ads cost.  This is essential for selling on amazon.  This will be higher for new products.  I usually budget about 5% of sales price overall.  Storage Costs: Amazon charges storage fees for items that sit around too long (use calculator) Inventory placement fees: Cost to send product to one FBA centre.  About 40c per unit Labelling fee: Cost for Amazon to label your products (you can do it yourself to save this). About 50c per unit.   Deduct all of the above from your sales price to get your gross profit margin! Amazon provides an excellent calculator to help you define all these costs and compare to FBA vs self fulfilment, you can find it here