This is a humble topic, borrowed from Aquaria's Steam Game Center.
If you didn't noticed, Aquaria wasn't discounted on any larger Steam Sale for some time now. Nearly every larger/smaller game have at least -50% price cut during the sale, but Aquaria isn't the case. There are only few of examples of games that wasn't discounted on Steam (Summer Sale, or Autumn Sale).
There sre some people that are waiting for opportunity to grab the game cheaper, since they are not sure if the game is worth it. As a mega fan and owner of Aquaria I'm sure that it is worth even more than 10$, but every price cut may convince people. Many gamers didn't discovered this gem, so maybe give them another shot?
I posted that thread because it was rather strange to see every single indie game on Steam discounted, except Aquaria. This game needs more love! and players!