If the crypto market shows a positive development until end 2018. My personal expecation is at least a x4 in market cap. Then Ether will be ~5000USD at year end.
Not so easy. It is possible between 2-4000.
it is not possible easy eth price up to 5000USD but I am sure eth price will get better even bounce high.
because the flatform eth project is very promising and gives almost the same results as bitcoin. so I think the eth price will improve this year.