Once you create a product in your dashboard, you can easily access and edit your products to change their initially set parameters (i.e. the price, type of item, or description):
Click on Marketplace from the left-hand menu
Select the product you wish to edit
A edit panel with appear on the right of the screen. Change or add any settings you deem fit
Click Save at the top right of the edit panel to cement in your changes
Need more info on Marketplace?