We're talking about the utility function of money. With enough money, it's definitely the case that it goes down, but I think it goes up faster than the apparen

We're talking about the utility function of money. With enough money, it's definitely the case that it goes down, but I think it goes up faster than the apparent value for a bit as well. £20k is more than twice as useful as £10k is more than twice as useful as £5k. Where the crossover is, though...