Update: Here's the official word from Best Buy.
"It was a momentary pricing error. The correct price is $299.99."
We've got word into Best Buy corporate to help clear things up, but we're willing to bet this is what happened. AC reader @boomstickah points us to this shot snapped by @nutzareus of a correction notice at his Best Buy store, saying the Best Buy website incorrectly listed the HTC Flyer at $99. That makes a little more sense, no?