Last time Gameloft tried to charge $9.99 for a game,  it ended badly.

Granted, Terminator Salvation wasn't a particularly amazing game, and it was short.

Small wonder then that the flexible pricing afforded by the App Store saw Gameloft dropping the price within four days of launch to $5.99. Indeed, it was down to $4.99, two weeks later.

Things look much better for Avatar: The Game (or James Cameron's Avatar as it now appears to be called).

Not only have the reviews of the film and game been positive, but Gameloft has clearly learnt a lesson in terms of the quality and amount of content expected for such a premium price point.

Two charts and a gap

Perhaps more important though is the way it subverts the Top 100 paid chart; previously viewed at the main chart in terms of consumer discovery.

Because of its price, Avatar doesn't appear in the US Top 100 paid chart as this is organised by number of downloads. Clearly, it's unlikely to out download many $4.99 games, let alone anything cheaper.

But when it comes to the US Top 100 top grossing chart, Avatar is at #33 (at time of writing).

Indeed, looking down that chart - a lot - you can even see Live Poker Deluxe 5M by Zynga, priced $149.99, sneaking into the Top 100 at #96.

Back in October, when the Two App Stores model was proposed by tumblr designer Marco Arment, it seemed to be a solid intellectual argument.

Now however we can name those two App Stores: the paid chart for 99c games, and top grossing chart for $4.99 and above games.

The significant trend for 2010 will be what happens to the middle ground.