Answer:
I am often sold by children entrepreneurs in summer time
I have an eye, but I can't see. I usually have to work with something in my eye. What am I?
Some will use me, others not. Some have remembered, others forgot. For profit or gain, I'm used expertly. I can't be picked off the ground or tossed into the sea. What am I?
I am black within and red without; with four corners round about. What am I?
A dragons tooth in a mortals hand I kill I maim I divide the land.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.