Answer:
I have numbers on my face but can't find 13 any place. What am I?
When you stop and look you can always see me. If you try to touch you cannot feel me. I cannot move but as you near me I will move away from you.
I am an instrument that you can hear but cannot see or touch. What am I?
I can be simple or I can be complex. I can be found in this riddle or in everyday life. I can be shapes or even colors.
I am a box who holds keys but not locks. With the right combination I may unlock your soul
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.