Well nobody can predict it correctly, but obviously it is going to go up again since it's market capitalization is growing everyday, but i think it will take some time to be $400 again, we are going toward it but a little bit slowly, probably it is going to be $500 before the end of the year, nobody knows it well, but i know that it has that potential to grow that much.
Anyway, keep investing in it, i would not dump my eths until i see a fair price.
Maybe the price will be over $400 again after some big usage of ETH appears.