This would be similar to Heroku's treatment of "apps." You can work and collaborate with others on an app -- say as a consultant -- then when it's time to deliver the product to a client or otherwise hand it off, you can easily transfer everything to another billed account. This might actually increase the adoption of Aha.io because the receiving account would have incentive to sign up for a full team account to continue work on the product.
Thank you for your idea. This article describes a process for moving data between Aha! accounts. Alternatively we have a fully featured API which would allow for transferring data.
At this time based on the two options above and current priorities, we are unlikely to implement this idea. We hope you understand.