What is the point of this? Many people find it insane (some even find it offensive) to have e-books priced the same as regular print books. E-books are much cheaper to produce than print books and, therefore, should be priced lower. Authors like Joe Konrath have argued that the sweet spot for book pricing is around $2.99. Other authors like Amanda Hocking (before she signed her deal with St Martin's Press) have gotten away with books priced higher than that, but still below that magic 9.99 number.
Where did this number come from? Apparently when Amazon got started with a Kindle device that cost $400 their sales pitch was that readers could save $20 per book by buying e-books at $10 ($9.99) instead of the hard cover for $30.
At first when the print publishers saw the e-book market as a source of additional revenue there was no problem. However, when it became obvious that the e-book market was growing at the expense of the print market, the $9.99 price became a point of contention with the print publishers trying to protect their paper sales. This is a fight that still goes on nowadays. But that magic "9.99" number got fixed in the psyche of Kindle readers spawning such things as the 9.99 movement.
I personally think authors can charge as much as they want for an e-book. However, I will seldom buy e-books priced above $5.99 (it goes without saying that I think that even $9.99 is too much to charge for an e-book). I will not vote for boycott tags or write a review solely based on price (although it is a factor). But I think pricing is a very important thing to consider when publishing your e-book, lest you want to incur in the wrath of the 9.99 Boycott crowd!
Please check out my first collection of short stories, The Sun Zebra.