Coming out on Dec 11. in Japan, for 9 800 Yen. Comes with a special decovrative sleeve and some stickers. Only for the 3DS version (even though it would've been neat for the Wii U version too... though not really useful).
Source
Smash 3DS solo: 5.200 Yen
Smash 3DS solo x2: 10.400 Yen
This dual gift pack: 9.800 Yen