Can you please give me some advice on going to a Dermatologist?

I am 14 and i have average acne for a teen but i really want to go see a dermatologist about it. Do you know how much it is to go see one? A session? Does it help?/Did it?Can you please give me some advice on going to a Dermatologist?
do you have insurance? They are not a cheap visit. I have found that the Dermo. did not tell me anyting that I alread know about my acne. She told me to use Purpose soap and Purpose lotion. She also told me to use Dove for sensitive skin soap, and Aveno oakmeal soap. You can seach for answers already touching this subject. Unless you have really bad acne, I would save your money and try over the counter products.