You better stay away from that drug or skip the idea of selling it online. Agreed that bitcoin would be anonymous way to get paid but you still have to make a deal for sending that drug physically to some address or visit the person of interest. So much danger is involved. Who knows what Feds are upto and if they track unusual activity through bitcoin then that will initiate track order on your IP address.  This is not Hollywood move mate, its real life. Try something different.