For queues - cost is only deducted when a viewer is drawn from the queue.
Real Life Example: You are standing in a queue for something (e.g. deposit money) ... before your turn comes the bank closes...so you still have the money. Only when you reach the counter, are you able to deposit money.
Gaming Example: 30 People join a queue to play with you. You play games with viewers and keep drawing viewers from the queue. After going through 20 games, you say its the end of the stream. The 20 people that played with you would pay the queue cost, while the last 10 that joined but could not play will be refunded their points.
