You don't
buy BCH. That's silly.
It comes free just by holding your BTC.
Not for people who are buying BTC
after the fork occurred, they get nothing for free. And the BCH cartel knows this. They know that in order for BCH to survive into the future, it's not enough to have existing holders. They must have new buyers, now and into the future. For decades. And someone's got to buy all the existing free BCH coins being traded for BTC.
Ain't gonna happen.