Don't know how long it may take, but any price between $500-$1000 is a decent price for ETH IMO.
And if BTC spikes to a new ATH then ETH may also lead to a new ATH. Then ETH may have a price above $1500.
Another thing is, nowadays I'm seeing so many projects are moving to their own blockchain, leaving ERC20 tokens.
So it is good or bad for ETH, not sure yet, still observing!
#5 Brian Schuster Ethereum Price Prediction 2019[/b]
The founder of Ark Capital LLC, Brian Schuster made a very bullish and optimistic prediction. He believes that Ethereum may reach $100,000 in another 5 years or so, and will eventually replace gold with crypto.
The person who predicted $100k in the next 5 years is totally unrealistic.