The forked currencies are just the same as altcoins, you can't sell 1 Bitcoin Cash for $7000. The fact that people are willing to accept money for them doesn't change the value of one Bitcoin.
You can, it's confusing but there is Bitcoin, Bitcoin Cash, Bitcoin Gold, and soon to be another one Bitcoin Segwit2x or some such.
Each of these other "versions" of bitcoin were created by a fork. As far as I know, when a fork happens you get an equal number of "new coin" as you have original coin. Seemingly creating value out of nothing.
Ah I missed the different name. Thanks for the clarification. I was thinking of comments I've seen before where people say that if you have 100 bitcoins you'll have a hard time converting them to (e.g.) $700k cash.
My understanding is that most exchanges won't allow you to move more than $10k/day or so out of your account. So, if you use three separate exchanges, it might take you a month to liquidate the entire stake.
Bitcoin Cash was born out of necessity to save Bitcoin from disaster when it was hijacked by corporate interests (funded by AXA/Mastercard).
Both sides of the SegWit fork (SegWit1X vs. 2X) ~Nov. 16) are intentionally crippling transaction speeds/costs to move transactions off the blockchain and into the pockets of said corporate interests.
The true spirit and potential of Bitcoin lives on through Bitcoin Cash.
That could be entirely true (and I believe there are several alts that are technically superior to BTC), however if a friend asks me for Bitcoin, I am not going to tell him to install a BCH wallet, send him BCH, and tell him not to worry about it because it's Bitcoin in spirit and it's going to be great.