Guitar Hero World Tour came out a couple of weeks ago and it doesn't look like the economy is hurting sales at all. The full band package with the guitar, drums, and game is selling so well it is hard find at retailers even though it is an almost $200 item.
The Wii and 360 versions are selling for more than MSRP. The Wii Guitar Hero World Tour is selling for $277 on average and the 360 version is selling for about $200 (just slightly over retail price). The Playstation 3 version is the only one where resale prices are below the suggested retail price. It's selling for $163 on average.
If you already own a Guitar and just want to buy the World Tour game or Guitar Bundle you don't have to worry about trying to find the games, they are plentiful and resale prices are below MSRP. Following the trend for most games without supply issues.
The prices appear to be coming down from October to November so Activision must be shipping more of these to stores.