It wouldn't hurt to be but if you just wait and get Sheppard air when you get your atp-ctp class date they will send you an access code and it's free. You should have plenty of time to study Sheppard air from indoc then through the course in Dallas, as long as you study how Sheppard air tells you to. It's not bad don't worry too much. But if you really want to you can probably get Sheppard air early and have them reimburse you when you get the ctp class date and everything. Good luck!