I went to Best Buy today and they said it was a misprint and was suppose to be for a controller or something. But then I went to their web page a couple of minutes ago and bought it for $19.99, and chose to pick it up from the store. So I'll go to the store tomorrow to pick it up while only paying $20.
Paul I think you got a misinformed clerk. As of the time of this post, it is STILL $19.99 on their website. If this was a misprint and someone in the company knew about it (surely the clerk told the manager who would have alerted BB HQ - that's what any anal-retentive clerk who refuses to give you the advertised price would do) and it would have been corrected both in-store and online.
Furthermore, at my Best Buy it was on the computer (hence it wasn't even questioned) and at the actual video game stand it had an "AS ADVERTISED" stickerfor $19.99.