Tracking Actual Revenue of a Campaign

Tracking Actual Revenue of a Campaign

It appears that when adding a contact to a campaign, I cannot modify anything other than the member status. What I want to be able to do is enter how much the person paid to attend the campaign (for example) and then be able see a total revenue of all contacts associated to the specific campaign. Just watched a demo webinar for Salesforce and this was a solution they have, so I thought, why can't I with ZoHo CRM. Essential, I have the Actual Cost, Budgeting Cost and Expected Revenue populated manually, but actual revenue is missing.