How would you price a Fright Check limitation?

[Pursuivant]

What would be a fair price for a new limitation which requires you to make a Fright Check each time you use a power?

I've notionally priced it at -15%, in line with a severe Phobia with a self-control roll of 6- and an Accessibility limitation ("Only When Using Power"), multiplied by 80% per Temporary Disadvantage. Add -5% per extra -2 to Fright Checks. Double costs if you must make a Cosmic Fright Check, which ignores Combat Reflexes and Fearlessness and limits the effectiveness of Unfazeable.