Supplement, is it necessary?

[Robelus]

Hey everyone, before I post my question I just want to give a you a quick info about my background. I am 18 years attending high school, and I do not have a part time job , and I am planning on starting P90X on February, before I do so I want to get my nutrition right. Now to the question, I think the title should have gave it away, are supplements important for muscle gain, if so what kind should take, because at the moment I am financially stable to buy Whey protein, if you guys think there are better or important and cheap supplement than Whey protein, just let me know. Please and Thanks .