Aaaah, nice. When it comes to Collecting then sometimes you know HOW but not WHY. At least when the Trinity of Cartier-Knowledge (John Goldberger aka Auro Montanari, Carson Chan aka WatchProfessor (!sic :-) and Su Jia Xian) comes together and tells you exactly this HOW -- "How to Start a Cartier-Watch-Collection?".

Well, I am not the reference, sure. But for me the first question when I make a decision is not HOW to do it but WHY to do it!? And I would formulate an initial question exactly like this: "WHY to Start a Cartier-Watch-Collection?"

Simply, is there a good reason to do it? To find out, it makes sense to ask hypothetically: "What Happens if You DON'T Start a Cartier-Watch-Collection?" And now your answer is

• "I would get 95 points less on my personal happiness-scale!"
• "I am trying to do what most others do in my peer-group!"

Well, in that case: GO! Start right away... but before make sure to check HOW (see above). Or is your answer to the hypothecial question

• "I want to make a difference: I want to preserve and carry these pieces of art into the future."

Now, in that latter case we could note that a "How to" would not make any difference besides the increase in price of what is desired, cared for and preserved by others a lot already: anyone of the dozens of under-bidders would preserve them and carry them over time into the future, anyway. Face it: you do start it or not... it makes no difference besides a increase in sale-price, and so significantly for the... seller.

Ad 20241122: I really get in good mood and excited when people call themselves "Professor of Horology" or "King of Old Watches" etc -- academic and aristocratic references; what could go wrong here? :-)