I have to disagree with
@LoodeX. The name is absolutely worth renewing. You paid $300 for it after all, and while it may not be the most popular of names, it's one that people know, it's in .com, and a first name is a first name.
It's been registered in several other extensions - Good sign.
Several other Elianna + "last name" domains have also been registered - Good sign
Clearly some other domainers liked it enough to bid with you at NameJet - Decent sign
The one bad sign is that I can't find any businesses using this name for branding. That's disappointing, and certainly hurts the value and makes this more of a long-term hold, but absolutely hang onto it. Ideally someone with a personal connection to the name will come looking. And if the name is indeed growing in popularity, then you may see more active websites starting to use it.
I would look for between $5K and $10K from an end user, and would not be in any rush to sell it. Some would push for more; others would take less. That decision is a personal one.
Good luck with it!