This plugin adds a permission shop to the server the plugin is installed on. In this shop players can buy permissions with their money with these permissions the player unlocks new features determined by the server owner. The plugin has native support for some popular permission managers such as: GroupManager, PermissionsEx, and LuckPerms. It also allows users to add custom support for any command based permission manager of their choosing.
I have posted some screenshots of the plugin on the SpigotMC resource page.
The source code of this plugin is publicly available on my GitHub page.