Apple tend to discontinue the Pro and Pro Max iphones every year. A customer going into an Apple store will only see the 14 Pro Max, which might retail for $1200 base, and the 14 Max for $900. The 14 Max will surely a huge seller. Hunting for a 13 Pro Max (in the color and storage size that you want) when the 14 series are released might be hit n miss.
In fairness most who are buying older iPhones tend to buy via online. Music magpie here in UK is very popular