About 300$ agree. ETH is already close to this mark. In the past bullrun ETH was worth 1300$. When the price reaches this mark the next hysteria will continue. Despite the fact that some still call the project a scam.
ETH just made it to $300. 
The project that has been through its platform, through its smart contract are the scams. And ethereum foundation doesn't hold any way to stop them because it's open for every project.
It will ride the BTC's bull, we will see ETH reaching $300-$500 in no time.
I hope you are right
$500 would a great price to hand around stable for a bit but then hopefully climb further.
Are you going to sell @$500? or you will wait as it climbs further soon?
I intend to hold if it hits $500. I would be looking at $750 before I consider trading/selling. I only have a small amount of ETH so the impact either way will not be too much for me.