TOPIC: Automated invoicing?

Our client uses DT Register already for events. We'd like to start with member's details in CB and prepopulate that into an invoice with DT Invoice. It appears that's a pretty manual process. we could set up an event in DTR to handle this but the client wants an "invoice" sent to members, and she wants that member dues field in CB to prepopulate if possible to DTR?

Anyone build a member renewal system using these two things? I know there are subscription modules for CB but the client is already comfortable with DTR for events, we'd like to do something with it instead of another tool.