The Marketplace is a section of KoGaMa where you can buy models and avatars created by other users. You can also add your own creations to this section.
Just select the model/avatar you want to buy and unlock it. Below the gold requirements are listed.
Models cost 10 Gold, and those may be used for your game creations. The owner of the model receives 1 Gold and 50 XP when bought.
Avatars cost 140 Gold, you can individualize them and make them look like anything you wish. The owner of the avatar receives 14 Gold and 50 XP when bought.