Here's an excellent article on software pricing:http://www.joelonsoftware.com/articles/CamelsandRubberDuckies.html
One of the biggest questions you're going to be asking now is, "How much should I charge for my software?" When you ask the experts they don't seem to know. Pricing is a deep, dark mystery, they tell you. The biggest mistake software companies make is charging too little, so they don't get enough income, and they have to go out of business. An even bigger mistake, yes, even bigger than the biggest mistake, is charging too much, so they don't get enough customers, and they have to go out of business. Going out of business is not good because everybody loses their job, and you have to go work at Wal*Mart as a greeter, earning minimum wage and being forced to wear a polyester uniform all day long.
My take on pricing in games is that a lot of it is about positioning. In the world of business software it's common to hear of people raising prices and actually selling *more* units as a result. So depending on the product, price is a signal of quality.
That's why I thought Aquaria was priced pefectly at $30. That game oozes with quality and the "hand-crafted" feel that makes it worth far more than the standard $20 price point.
I also thought releasing Everyday Shooter at $10 was a mistake. That was the game that seemed to define Indie in the mainstream press -- if a typical gamer wanted "indie cred", that was the game to buy. And since there's nothing else really like it, they could've charged at least double. Giving it a budget price can only add to the perception that indie games in general are not worth the "risk" of paying full price. I don't think Indie movies or music operate this way, so why would indie developers sell themselves short? The fact that we see our games as much more than just a commodity makes them worth more, not less.
Lowering the price after the fact can sometimes work, though. For one, it's another excuse to get some press, which is always hard to come by. In my own case, I dropped Joystick Johnny from $19.95 to $12.99, partly because my positioning is about quick, cheesy games. I wish I had enough volume to give an accurate percentage of the conversion rate, but unfortunately I don't. It just felt right to me for what the game is.
Or if you don't want to lower the price, you can just keep adding more updates. I know that the creator of Pretty Good Solitaire has done well by continually adding games to it. Joel Spolsky, for his bug-tracking software, has said that the one thing that always results in more sales is releasing a new version.
In my own case, I recently added the ability to share a full version of the game with up to 3 friends, because part of the value is competing on old-school high score tables. Though if I had more time, I would probably be adding more and more minigames, since it's pretty scalable that way. With enough minigames, I would consider raising it back up to $19.
For most indie developers, I would say: Don't sell yourself short out of some misplaced guilt or the idea that a lower price will magically lead to a feeling of goodwill from the players. I think most games, even a lot of mainstream games, are priced too low considering the huge investment that goes into them, and the value that players get in return. Try to compete on innovation, imagination, and spirit, not price.