Price cut on "Golden Sun: Dark Dawn" for the Nintendo DS on Amazon and Gamestop for $19.99. Not sure if the prices will jump back up like its GBA counterpart. But according to camelcamelcamel.com, it was $34.99 just a few days ago on Amazon.
http://www.amazon.com/Golden-Sun-Da..._1?s=videogames&ie=UTF8&qid=1302879246&sr=1-1
http://www.gamestop.com/browse?nav=16k-Golden+Sun+Dark+Dawn
http://www.amazon.com/Golden-Sun-Da..._1?s=videogames&ie=UTF8&qid=1302879246&sr=1-1
http://www.gamestop.com/browse?nav=16k-Golden+Sun+Dark+Dawn