Kidizen seller fee calculator. Calculate your total Kidizen seller fees, profit & margin. Kidizen Fee Calculator Selling Price * $ Cost * $ Calculate Frequently asked questions. What are the Kidizen fees? Kidizen is an online marketplace for buying and selling secondhand children’s clothing, accessories, and gear. Kidizen charges a fee to sellers for each successful transaction. There are no listing or transaction fees. What is the Kidizen transaction fee? Kidizen charges the seller a 12% + $0.50 fee for each sale on its platform.