One off pro posts

Hello, 
I’m currently on the free plan, I will probably at some point become a pro user but as it stands I’m not ready to become a pro user.
However I would like to gather email addresses to build an email list which I know is part of the pro plan.

What if you were to offer a pro option for one off post so I could gather this information for a small fee?
Might cause you a headache to figure out but it would simplify my life a bit :) 
Thanks 
Ashley