I'm pretty sure this is the rational, utility-maximising preference for anyone who isn't already a multi-millionaire. The diminishing marginal utility of wealth

I'm pretty sure this is the rational, utility-maximising preference for anyone who isn't already a multi-millionaire. The diminishing marginal utility of wealth means that $1 billion generates way, way less than 100x as much utility as $10 million for the vast majority of people. And if you need another reason (I wouldn't), there's the time aspect as well - how much is $1 billion in ten years time worth today? A lot less than $1 billion to me.