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?
The main point is if you can afford to buy some coin or Ethereum then go for it . Ethereum's price right now is very low than the usual so it is a good opportunity to start an investment , you don't know what will be the next price of ethereum so if you can afford it then buy it.