Because it was worth a little but not a lot to him? I'll pay $20 for an audiobook, but I won't pay $100 for one.

One might be surprised by the proportion math of one's $20 as % of one's earnings or net worth versus his, and how far the same % could go.

Because billionaires can't love anything more than they love money.

Sounds like you're more obsessed with money than he is. He spent a billion dollars on a terrible Tolkein show.