Answer:
What is easy to get into but hard to get out of?
I am often sold by children entrepreneurs in summer time
What gets sharper the more you use it?
you can throw me away but I will always be coming back
I'm sometimes white but most often I'm black. I take you there but never bring you back.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.