When in Japan, trying shopping at a duty free Donkii Houte store. You save 5%, although they do charge MSRP rates.
Anyway, the GameCube is also 14000 Yen in Japan, about $125-$140, give or take. Definitely overpriced, and their hardware includes no game (such as Metroid Prime or the upcoming MKDD), nor does it include a TV adapter. No wonder GC sales are so low out there these days.