The AP has published an article stating that deferred action application fees will be $465 — which makes sense, considering that an application for work authorization costs $380 and biometrics cost $85, totaling $465. If this is true, that means there will be no additional fee for the deferred action application.
There were internal discussions within USCIS to charge an additional fee for the application, but as of now, either there is no additional fee or the number has not been determined. We will know more on August 1 when new guidelines are released.
Please visit our Dream Act Deferred Action site to find answers to your questions regarding the process.