I would look for the best condition, late 18238 that you can buy, the state of its 83858 President bracelet being your primary focus.
That model's 3155 calibre movement offered the double-quickset method of changing Day and Date quickly and independently. I don't see any great value in later tweakery to the engine.
The 118238 series saw no significant improvement except (after a year or two) the introduction of the 83208 bracelet with a better clasp.
I would not buy now unless you have to. In my view prices will be lower in a year or so as "The Great Correction" plays out.
Whenever anyone looks at such graphs, they should remember that they illustrate ASKING prices, not actual selling prices...and ones that need to be understood in context The section showing recent times actually inflates real market prices for willing buyers and sellers, believe it or not, as its data includes the asking prices of many desperate sellers chasing their money and trying to find a mug willing to pay last February's price.
H