What happens when greed touches innocence?

Based on this story, when greed touches innocence, innocence is destroyed. Paul is this story's innocent character. He's young and naive. He doesn't have a firm grasp on wealth, poverty, and financial situations. All he knows is that his mother is unhappy with her life. He knows that her unhappiness stems from the fact that she wants more. She wants more stuff, more money, etc. She's very materialistic. She's greedy and not content with her current blessings. She's not exactly a pauper, yet she is not content.
This general unhappiness and greed for more is what pushes Paul toward his rocking horse gambling scheme in the first place. Paul's winnings are able to bring much happiness to his mother, and he doesn't want her to be disappointed in the sudden stoppage of the money. He pushes himself so hard to keep giving his mother more and more that he dies from his efforts. His mother is not the only greedy character to work toward Paul's destruction. Oscar is just as guilty (if not more guilty). Paul's mother is unaware of her son's talent; however, Oscar does know about the skill. He abuses that skill for his own personal gain, and his greed causes him to push Paul to the ultimate breaking point.

And in spite of himself, Oscar Cresswell spoke to Bassett, and himself put a thousand on Malabar, at fourteen to one.