I agree. One more time: You asked: "Why didn't anyone just enter the market and undercut De Beers?". The answer for a long time was: "Barriers to entry, and l

I agree. One more time: You asked: "Why didn't anyone just enter the market and undercut De Beers?". The answer for a long time was: "Barriers to entry, and low probability of success given the risks involved". This has nothing to do with not understanding pricing strategy. I don't know what you are arguing about anymore.