Pricing schemes seem like a ridiculous game, but everyone does it.
Products are always priced as $19.99 instead of $20, and offered discounts such as a larger version for the price of the small version. Do these things really matter? Are we really tricked into buying things because someone has tricked us?
I found this article on 11 Ways that Consumers are Hopeless at Math that points out and explains some of these pricing schemes. I know when I need to price something effectively or sell something on commission I will be studying this trickery!