According to the principles in this story, is a large donation always considered more valuable than a small one?

No, the teachings presented in Chapter 47 clearly state that the size of a donation is not the primary measure of its worth. The true value of an offering is determined by the sincerity and love with which it is given. The text makes this point explicitly: "What is given without love, out of pressure or obligation, Does not please God; even a little given with love has great value." This idea is reinforced when the wealthy man's wife receives a vision telling her that her personal faith is enough and that "One penny given with a sincere heart is worth a million." This demonstrates that a small offering from a pure heart is valued far more highly than a large one given reluctantly.