Correct me if i'm wrong, cause i'm a noob as well  but i believe its due to supply and demand and how easy it is to gain it.
If you compare it to precious medals with a limited supply and demand is relatively high, price will go up. For instance if you could get gold easily and everywhere in the world without a lot of effort, the price wouldn't be as high as it is now. Cuz it is easy to gain, supply is high, and demand will be lower.

So imo, xvg will be implemented to some extra exchanges now since it won some polls, people are getting more interested, it is getting more known, 'brandawareness' increases, demand will increase so price -can- go up.
But since there is still a lot of supply, it will not go sky rocket yet.
Of course there are still other variables which affect the prices...