This configuration is where the site owner and possibly a few other sellers wants to be the only one to be able to place auctions or classified ads into the system. All other users in the system would be able to view classifieds and auctions as well as bid on auctions but not be able to place listings into the system. To have this type of configuration you will need to have the Enterprise pricing addon installed and enabled. The key feature you need from these editions is the ability to have more than one user group and price plan in the system.

Within you user group and price plan admin tools you would need to have at least two price plans. One for the "seller(s)" in the system that has a max listings allowed configuration to a high number and any other charges/fees or features you want those users to have.

The "buyers" price plan would have the maximum number of listings allowed in the system would be 0. You might also want to make sure these users do not see specific links in their client side admin tool.

Within the user group admin tool you would create the "buyer" and "seller" user groups and attach the appropriate "buyer" and "seller" price plans to each. Then make sure the "default user group" is the buyer user group. Next make sure that neither of these user groups have registration codes within them. You only want new registrants to have the ability to register into the buyer user group. But note that you can manually move any users from the buyer user group to the seller user group at any time if you want to have more sellers in the system.

You will need to make sure that you do not use the admin user to place listings. Register a user into the system that you will use as the seller and then manually move that user to the seller user group after registration. You can do this by editing the details of that user within the admin tool.

Within the "buyer" user group admin tool you may find it easier to remove and client side admin links to managing current or past listings or any other links to such listing management features you do not want them to have access to or need access to.

You would need to have two user groups and two price plans. One user group/price plan would allow it's users to place listings while the other would not. To add more than one user group or price plan into the system you would need to first turn on the Enterprise Pricing addon within the following admin tool:

ADDONS > MANAGE ADDONS 

This makes the "add new user group" and "add new price plan" links appear at the bottom of their respective admin tools:

USERS / USER GROUPS > USER GROUP HOME
PRICING > PRICE PLANS HOME

By default you have one fee based price plan attached to the default user group. Within that price plan you would change the following setting to "0":

PRICING > PRICE PLANS HOME > [EDIT] (next to the price plan) > COST SPECIFICS > Max Listings Allowed (per user) at One Time

Doing this makes the default user group user to NOT have the ability to place listings into the system. Also note that this default user group is the user group all users are automatically registered into if the registration code feature is not in use. Now you need to add a user group and price plan for the user(s) that will have the ability to place auctions and/or classified ads into the system. First add the new price plan here:

PRICING > PRICE PLANS HOME > [ADD NEW PRICE PLAN]

and within that price plans admin tool at the setting below set the max amount of listings to as high as you want:

PRICING > PRICE PLANS HOME > [EDIT] (next to the price plan) > COST SPECIFICS > Max Listings Allowed (per user) at One Time

Now go to the following admin tool and create a new user group:

USERS / USER GROUPS > USER GROUP HOME > [NEW USER GROUP]

and attach your new price plan to that new user group. Make that within the following admin tool that the default user group is the user group/price plan that does NOT have the ability to place listings (max listings allowed set to 0):

USERS / USER GROUPS > USER GROUP HOME

Once done your configuration is basically done. Any user that you want to give the ability to place listings into the system will need to register into the system. Then you as the site admin will need to manually move them over to the user group/price plan that has the ability to place listings. DO NOT USE THE ADMIN USER TO PLACE LISTINGS. Create a new user in the system by registering them normally on the client side or adding them within the admin tool. Then edit that user and manually move them to the user group that has the ability to place auctions and/or classifieds.