Ignore the money for a second (difficult, I know), and think back to this moment the next time in your life you come across a perfect cased set of Joe Manton duelling pistols (which will probably be never).
Back to the money. Yes, its crazy. But cheaper than some are willing to pay for some factory-assembled one-of-300,000 Winchester or Colt. Also much lower than people are ready to spend on sports memorabilia, movie star apparel, or other pop-culture trinkets.
I think the new owner is probably very happy with the price.