No hat is worth $2.4 million, and the fact that someone felt the need to spend that kind of money on an item just shows what the super rich values about society. Think about what kind of good could have been done somewhere for $2.4 million. Clearly the super rich just don't have anything better to do, and spend their wealth because they can.
You have to spend money on something. Wealthy people are able to spend as they please, and some have obsessions with collecting, just like regular people did with beanie babies. It is fun to hear about what rich people have bought with their money because some of it sounds over the top.
If I had that much money to waste, I would use it to wipe my crack. And that'd still be a better use for it. Why would you spend over $2,000,000 on a hat you probably can't even wear. I'd be happy if I was the one selling that mother fricker, which may mean it's a good thing to buy it. I'd flog it off for $4m a couple of years later and maybe buy a mansion. A hat could get you a better house than you'd ever get working a thousand jobs. Makes you think, huh.
To some extent, it seems silly that Napoleon's hat would sell for such a ridiculous amount of money. However, important historical items are very valuable, and tend to hold their value very well. Purchasing something that will only increase in value over time is a very wise investment - particularly when the global economy is so unstable.
Of course rich collectors are not just bored with their wealth. They are as passionate about their collections as other collectors but fortunate to be wealthy enough to fully indulge them. Would I pay 2.4 million for Napoleon's hat if it was just pocket change to me? No. But Napoleon is not my passion and I don't care to own his hat.