You are right. I expressed my thought sloppily.
"Half of the BTC value at the time of the split has been traded..."
Ultimately implying that the mere existence of a new chain does not mean there is actual value stored in it.
Lets say that 10 million BCH have been traded in the next week, and price ends up at $5. At this point the selling pressure will stop, and it could be a good moment to buy. After all, all those 10 million did find somebody interested in buying them.
As for actual value, there is no other value other than somebody willing to buy them from you, and this is true for both BTC and BCH.