Unfortunately such feature is not available, but is planned for a later release. You could create 2 plans and develop a new CB plugin to use jQuery to move it inside of the display box of another plan like you've shown, which would give the illusion of having said feature.

Actually, you could implement that in your own specific CBSubs template.

Unzip and rename the rounded template, edit the XML file to change to your own name.

Then you can edit the views and render as you wish each plan. It's probably a bit tricky to do, but with clever use of CSS it's achievable.

EDIT:

OR simply override the CBSubs view in your joomla template as with any other standard joomla override. The path where to put the corresponding overrides is shown in the template tab of the CBSubs settings.