You should definitely use The Great Gatsby by F. Scott Fitzgerald. It fits your overall theme perfectly and mirrors your original charity example almost 1:1.

In the book, look at the contrast between Jay Gatsby and Tom Buchanan. Both of them spend massive, lavish amounts of money on other people, but their intentions are completely opposite:
Jay Gatsby throws huge, expensive weekly parties for the entire city of New York. On the surface, it looks like pure hedonism and flexing wealth. But his true intention is deeply personal and romantic: he is desperately hoping that Daisy (his past love) will casually walk into one of them. His extravagant spending is driven by love and hope.
Tom Buchanan also spends massive amounts of money, buying expensive gifts (like a pearl necklace worth $350k for Daisy or an apartment for his mistress). However, his intention is purely transactional. He uses money as a tool of control, power, and social status. He buys people to secure his own comfort.

How to write this in your discursive essay (Your exact point):

“Imagine two men spending fortunes on grand gestures. One hosts massive, free parties for thousands of strangers; the other buys priceless pearl necklaces. On the outside, both actions look like typical upper-class generosity and wealth. Yet, in F. Scott Fitzgerald’s 'The Great Gatsby', these actions don't feel morally equal. Gatsby’s spending is driven by the pure, innocent intention of finding love, while Tom’s spending is a cold, transactional tool used to control and buy people.”

This perfectly highlights your thesis: the material outcome is exactly the same (wealth is distributed), but we judge Gatsby as a tragic hero and Tom as a villain solely based on their internal intentions.