To add new price plans and user groups into the software you would need to install and enable the Enterprise Pricing addon within the following admin tool:

ADDONS > MANAGE ADDONS

Once done you will see the "add new price plans" button as you see in the following screenshot:

Once you click the add new price plan you will see a choice where you need to choose the type of price plan: subscription or fee based.

Within the above screenshot you see:

1. The admin tool name for the new price plan. This name will ONLY appear in the admin tool and NOT the client side
2. Choose the listing type this price plan will apply to
3. This is another setting that will ONLY appear in the admin tool and is more for your purposes to keep price plans straight
4. Choose whether this price plan will be a fee based or subscription based type of charging. More on the specifics of each elsewhere in this same section of the support wiki
5. After making all the choices you want for your new price plan click save to insert it into the system.

Inserting a price plan into the system does not automatically mean that people will use it. For a price plan to find use it must be attached to a user group and of course users in that user group. Any pricing a user group sees is based on the price plan(s) attached to it.