Eth will stabilize and go up in price after POS, simply because there will be smaller amount of coins produced daily, burn process will still cause deflation, staked eth will remove some coins from daily usage etc....
POS will displace small people from the system, game has become to big for small guys if you don't count in staking pools.
Price correction will come eventually, how long will it take? probably few years.
You should know that most of the PoS coins have failed miserably before and what does Ethereum have beside these others that it will continue to be successful after moving to PoS,nothing.Therefore if Ethereum moves to PoS I give it a few months only before it is completely forgotten from the map of crypto,the fact that Ethereum is so successful beside the problems it solves it is a PoW coin which a lot and I mean a lot of people are mining daily making it as famous as it is.One move away from such system is destined to go bankrupt and fail.
Most of PoS coins you saw already shit from the beginning. Some transit from PoW to PoS because they are already from their last leg. It's all thanks to the 2017 bull run that PoW coins or every coins got boosted so people think they were great and PoS was the problem. Big nope.
Can anyone here show me a great GPU PoW coin that is at the top10 in CMC other than ETH? How about top20? Even top30? See how GPU PoW was now at the last leg except ETH which is also soon to ditch it?
Before Ethereum there was Litecoin which was a GPU mineable coin at that time,precisely in 2015.This is to show that always in history there has been a top PoW coin leading and then every other type of coins followed,at least this is how I read it.
Anyway so far PoW coins have always been the better ones with a much larger market share as long as I know it is still Bitcoin and Ethereum the two big ones which have the greatest market share compared to almost all other coins,I doubt this will change any time soon,let alone if it happens because of a PoS coin.