The amount should be a result of your aspirations and your planning to achieve them.
To me, the premise for that calculation is money out, ie- how much are you willing to risk if the plan doesn't work the way you thought or hoped it would?
This consideration should include a contingency if your plan needs amending or if a new direction is needed. Frankly, I'd set that at 100% of the cost of the original plan. Thus, if a program enables you to test the waters for $49, budget for $100 plus whatever the initial marketing cost should be, and that figure should be advised by your mentor before you get started.
If you've bought into the concept of high-ticket programs, I'd still suggest you keep those funds on hand until you've become familiar with the entry-level costs. Then, if you're comfortable with everything, you can go for it with a much better understanding of the program's fundamentals and features.
And that's important: don't invest in anything you don't thoroughly understand. It may sound obvious, but this is a caveat emptor world. To thine own self be true.