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?
Seeing the current market situation, it may fall more. It is better to wait and see how low it may hit.
That's correct. Nowadays the market is falling, it's unpredictable situation, so it will be better to wait as you said and see if the market will be stable again or maybe grow or not, then we can decide if we buy ethereum or not, by the way, even right now, the price is cheap, so I bet that there are a lot of people buy ethereum with this current price, but to avoid any kind of risk we should wait a bit.