Why do some discontinued Rolex models consistently trade above retail? Take the...

https://city-wiki.win/index.php/Rare_Day-Date_Dial_Colors_That_Can_Push_Prices_Way_Above_Retail

Why do some discontinued Rolex models consistently trade above retail? Take the Kermit 16610LV or the Pepsi 126710BLRO, both with strong collector demand despite no longer being made