How do I price or assign a value to the extras that I offer with my course, such as a Q&A session, VIP Package, or bonuses?

The first thing to do is ask yourself, “If I were to sell this asset as a standalone product, what would I charge for it?” Don't inflate it or make it crazy high — just assign a reasonable value.  

It’s important to remember that your chosen values should always be less than your course price. You want your course to be the bulk of what your students are paying for; they are paying for your expertise on what you're teaching in the course. The extras are the icing on the cake. 

To be more specific, I would say that 70% of the value should be from the course and 30% from the extras if you choose to offer them. Charge accordingly.