I've owned two, the first one was £8.5k and the second a year or two later was £9k and people on here thought I was completely bonkers. Should have kept hold 😪
That said, the list price was £4.6k and basically it was a normal moonwatch with a fancy dial and caseback, so £4.6k was probably just about justified. Normal moonwatches were about £3.2k at that time.
Quality wise, it's still a £4.6k watch and worth no more, but if someone wants to own one they will have to pay that extra £15.5k for bragging rights.