You can add price categories that can be made available to members only.
When adding a members only price category to your event listing, click the "Advanced Settings" tab and tick the "Price category is available to members only".
For members to qualify for members only price categories, you'll need to ensure that they have a customer record with an associated membership number in your TicketSource account. You can add a new customer record by selecting the "Customers | New Customer" menu option, or modify an existing one by selecting the "Customers | Find Customer" menu option in your TicketSource account.
When making a new booking, customers who've selected one or more members only price categories will be required to confirm their membership by entering their membership number and last name.