It seems pretty much confirmed we can see Ethereum going under $400 these days.
Qn - Is it a good buy under $400 or wait for even more price drop?
I think the price of ETH will down to 350$ and will increase again
But it depend on you if you want to buy it and after that just hold it until the price recovered
This price can happen in today or tomorrow. I think the market is inclined to sell panic and this has a big impact on investor sentiment. Personally, I would buy ETH at $ 200 because this price would certainly be very low and I would keep at least 2 years.