How much will you need to sell to make paying commission worthwhile? It’s important to work out your costs carefully in order to not get swindled on commission or transaction fees. Remember that whichever payment processor you use will add a small commission too for handling the payment. Also, all products here are before vat has been added. (Correct at time of publication October 22) also, it’s worth factoring in marketing costs too as making sales is really due to your marketing efforts, your e-commerce store is just a tool. Marketing is what makes sales happen.