Please note the numbers may change from one question to another. A publisher sells books to Barnes & Noble at $16 each. The unit cost for the publisher is $4 per book. Barnes & Noble prices the book to its customers at $46 and expects demand over the next two months to be normally distributed, with a mean of 30,000 and a standard deviation of 8,000. Barnes & Noble places a single order with the publisher for delivery at the beginning of the two- month period. Currently, Barnes & Noble discounts any unsold books at the end of two months down to $2, and any books that did not sell at full price sell at this price. A plan under discussion is for the publisher to refund Barnes & Noble $3 per book that does not sell during the two-month period. Because Barnes & Noble shares the point-of-sales data with the publisher, the publisher does not require Barnes & Noble to return all unsold books for verification purpose. Thus, Barnes & Noble can still sell any unsold books at $2 each at the end of two month period. With the arrangement of the refund paid by the publisher for any unsold books, what is the unit underage cost for Barnes & Noble