Obvious Ideas

The massive Steam holiday sale was also a big win for Valve and its partners. The following holiday sales data was released, showing the sales breakdown organized by price reduction:
10% sale = 35% increase in sales (real dollars, not units shipped)
25% sale = 245% increase in sales
50% sale = 320% increase in sales
75% sale = 1470% increase in sales

(via http://www.codinghorror.com/blog/archives/001293.html)

Basically what they proved is that when a game is priced in a reasonable price they sell more. This way sells go up, privacy goes down and everyone are happy (besides the lawyers which have no one to sue for copyrights infringement).

Same thing can be learnt from the AppStore where $9.99 considered as an outrageous high price, but the app developers still make decent I come with those prices due to high volume of sales.