How much and how do you charge for a 15 hours advance excel tutorial

Hello I was wondering how much can I charge to create an advance excel tutorial that last 15 hours that has video lessons (demos), assessments (simulations), and multiple choice. Can I charge one time, if so how much? Or can I create a license that I charge for the creation of the content and a monthly fee to use the tutorial.

Captivate tutorial (Retake Quiz Tweaks)

Sample project about Themes, Timeline and Shared actions in Captivate. For the quiz slides distributed in between the content slides, the Retake functionality has been tweaked. Learner will not have to skip manually the content slides between the quiz slides, and also has the opportunity to retake the whole course after failure, instead of only the quiz slides.

Replay or Reset Slide (Captivate tutorial)

Captivate course about exploring Replay and Reset slides. It is a supplement to a text blog about the same topic.