Look at it another way, if you apply after 30 Jun, they will have to issue you with a new lifetime EASA licence because it will not be possible to add a rating to a JAA licence after that date. I am not sure what they will charge for the licence if your existing one has validity remaining, but what is certain is that when you reach the 5 year point of your JAA licence you will have to pay an issue fee for a new EASA licence.