So I made a prediction on Litecoin a few days ago that sparked a lot of conversation on the thread. It was very interesting reading the different thought processes and predictions. So I decided to do the same for Ethereum, however, I think that Ethereum has a chance to go beyond the 2-5k threshold in 2018, if only they would market a bit better. I believe that they need to get these new "coinbase noobies" to understand what Ethereum is and why it's significant if they want to stand a chance of getting above that threshold in 2018.
As always this is just my opinion and I would love to hear what yours is, check out my full thoughts in the video :
https://www.youtube.com/watch?v=mDiEVo7QZzQI think ethereum will go as high as $5,000 but like op said the developers need a lot of advertisements in other to go that high.