I feel it's annoying that a brand new CD or DVD will cost just the same across the marketplace, regardless of the band's popularity. Prices on the stock market for fluctuate based on speculation and general investor interest in that stock or commodity.

What if music and movie prices fluctuated on the same basis? Both industries keep careful watch of day to day sales of their titles, what if, by using the same algorithms that the stock markets do, as the demand for a movie goes up, so does its price, and visa versa.

This would of course mean that newer and more popular entertainment medium would be more expensive as everyone is buying it at once, but on the flip side, older albums and DVDs less in demand would be sold at a cheaper price, relative to the market demand.