Haircut Requirements

I don`t think a person should be "required" or "expected" to cut a person`s own hair. I`m a 16 year old MALE and my black curly hair`s about 2 inches below my shoulders. When straightened, it`s about 5 inches longer. I constantly argue with my parents about it, but I feel that as long as I`m paying for supplies [products, conditioners, and so on], I don`t think they should have a problem with it. I like the way I look, and with many teens my age having identity problems and an overall disliking of the way they appear nowadays, I should think that they`d be glad that I like the way I look and are happy with myself.