According to ICO, the current price is $ 4.5. It is interesting that the price of such a cooperative project does not increase much.
I think this is due to the fact, that you don't need BNT to use the Bancor Protocoll and the Bancor Website. All the transactions can be done in ETH. So BNT is basically the "fifth wheel on the wagon" (as we say in Germany). It is not really needed. The original promise to sponsor the gas for BNT transactions was not kept, so this was the only incentive to hold BNT over ETH.
My guess: The Bancor Protocol and the SmartTokens will thrive but no one will use BNT for this.