Is ap actually going to pay you to attend this event to cover it on your blog? No? Then why do you think it makes a difference if you go or not, seriously. I don't think posting a review on your ap.net blog is going to really help you get where you want to be career-wise, aim higher. It sounds like you really just want to go to this event for personal reasons.
No ap is not going to pay me to attend this event. It makes a difference to me because I know what something like this in a portfolio will help me do in the long run (told to me by much more important people than you will ever know). I am aiming higher, much higher. That is why this is important to me. And as for wanting to go to this event for personal reasons. That is completely false. If you have ever covered a major festival, you will know that you rarely get to see a set. You are stuck somewhere away from the music doing interviews or waiting for your next interview.