Allocation of IP Addresses

Jim Browning writes:

DeBeers has controlled (or at least significantly influenced) the price of
diamonds for decades, ensuring that they appreciate in value by controlling
supply, and by buying diamonds on the wholesale market to keep the price up
(similar to what countries do to protect their currencies). They could
flood the market at any time, driving the price down dramatically. Of
course this isn't in their best interest, so they won't do it. However
Russia might, as they have stockpiled large quantities of diamonds, and may
not have the same goal as DeBeers...

So in what way is this a demonstration of a monopoly able to
arbitrarily raise prices? What you've shown is that someone might be
able to arbitrarily drop prices...