Pricing Calculators
Fees are one half of the question; the price is the other. These calculators cover the arithmetic of setting it: what a percentage discount does to the price a buyer pays, and how much of each sale is profit once your costs are taken out.
Margin and markup are easy to confuse. Margin is profit as a share of the selling price; markup is profit as a share of your cost. A 50% markup is a 33.3% margin. The profit margin calculator shows both.