Seems to me that confusion is going to mean an ETH price of less than $0.25 for both forks, so the future relative price of them is not relevant right now.
So it seems this is mostly a shorting game now, to convert your ETH to BTC.
And/or to accumulate more ETH cheaply, in hopes it will someday recover and not go to $0 (i.e. die).
I don't think that it will lose value quickly. At most slowly capitulate because founders , developers, and original die hard investors hold most of the coins so the market cap can , misleadingly , remain high. I have seen many shitcoins last a long time in such circumstances. Where we should be looking is the moment when staff at the ETH foundation start leaving due to not being paid and a rush to switch to PoS - this will be the stronger indicator of problems.