RUMOR: Wii Fit+ for 2,000 yen or $21?

[silentmac]

So I'm confused. Is this an expansion pack or is it the first game with additional content added?

I'm asking because I'm wondering if I could sell my original disk for Wii Fit and buy Wii Fit Plus. I think the disk only sells for $20-$25 on ebay which which would finance the upgrade.

I'm doing the same thing with Metroid Prime: Trilogy. I'm gonna sell my Metroid Prime 3 disk to help finance the upgrade...