Terry Pratchett presents the "Sam Vimes boots theory" to explain this phenomenon. His character Captain Samuel Vimes of the watch observes:

  • The rich man can afford to pay $50 for a pair of boots that will last them 10 years.
  • The poor man buys $10 boots that last a season, because he only has $10 to spare.
  • At the end of 10 years, the poor man will have spent twice as much as the rich man on boots, and he will still have wet feet.