The cost for 1 coin is $15 though. If I count right the ICO price was $4 so that is 4 times as much, should probably go down in price later as most coins that come from ICO does? Better to hold off for a while?
These are IOU (I Owe You) markets, on which you can already trade coins that are not available yet. These prices are not accurate, they are determined by buyers who could not get in the ICO and are now willing to pay high above marketprice.
I tried to deposit another coin I bought on an ICO though to this exchange and it was not possible so who can actually sell there?
But you think it is better to hold of on buying and it is overprized now?
You can buy and sell there, you can't deposit or withdraw. Prices on exchanges or Bancor Network will be different for sure.