Once I learnt more about De Beers, I'm wondering if there is any other product that one could pull of such stunt and make themselves billionaires?

Step one - find a rare mineral that at this point has value close to zero. It is rare but worthless.

Step two - obtain monopoly on mining it or control it as much as you can (buy spots with dense occurrence, etc)

Step three - throw money at important and powerful people (such as Spielberg, so that in his new movie today's Marilyn Monroe is wearing your ore as a form of very high luxury) other media stars, politicians etc.

Step four - continue with excellent PR until enough wives or soon-to-be wives come to their soon-to-be husbands and request them to update their luxury status by buying your ore.

Step five - collect trillions of dollars across the globe, by tightly controlling your ore and its harvest.

Edit: step six - rinse and repeat for 50 years getting yourself even wealthier.