Answer:
The more you have me the less you see. Shine a light on me and I shall flee.
You used to come to me for all sorts of information and knowledge before the internet was born
I follow you all the time and copy your every move but you can't touch me or catch me. What am I?
I am an English word that is as long as I am valued. What am I?
I go through a door but never go in, and never come out. What am I?
Of these things - I have two. One for me - and one for you. And when you ask about the price, I simply smile and nod twice.