Agreed.
It's a real shame that prices are becoming so inflated by dealers and 'investors' most of whom have no great love of watches. For them it's purely trend spotting to make money.
Unfortunately, it's the way of the world today and we all end up following the trend if we find a 'Grail' etc.
It's such a shame that true enthusiasts (me included) are being priced out of the market.
In saying all that - the watch you highlighted at Christies is the regular triple date chronograph - it doesn't have the moonphase complication - which makes the difference in rarity and pricing.