The Payoff letter is probably not useful in a sale situation.

I would suggest that you find a Mentor you can work with who will help you out when you run into a situation that your prior training does not appear to have prepared you do deal with, based upon the questions being asked.

I learned a long time ago, that it is sometimes better for me to turn down a project, than try to move forward in an area that I do not have enough knowledge to properly complete the project.