.99 cent or not?

The question, if an author should make their work available for free or .99 cents have been a toss up and it really confuse me. If the readers are not willing to pay over a certain dollar amount then what should an author do? On the flip side, if an author make their work free, the reader becomes leary and usually don't read it anyway. I have found a midway point, I think... 2.99. What do you authors feel and what do the readers want?