When the price is constantly changing? For example, you purchase an app. at $2.99 only to see it drop to 99c? Or, even when it is offered for free? Does it make you appreciate the app. less when it becomes cheap? I know I shouldn't feel that way, but I do get a bit disgruntled when an app (for example, Top Gun) is sold and then the price drops and then drops again. Takes the charm out of playing it, admittedly, just a bit.