As I understand, WiiFit is sold out on Amazon Japan and being offered by secondary sellers, which is why it is so expensive.

Yep... How Play Asia gets it I don't know, but probably from secundary sellers as well since the price went up about 3 times. Feel a Japan PSP Deja Vu coming up.

amazon has it still in stock but it's topseller.
the second place is for the wii itself and mario comes at 23 now
no more heroes is low :(

x360 is standing above ps3 atm both in stock.

It's not being sold by Amazon, it's being sold by secondary sellers:
Check this google translation, the seller listed is Aichi/ok

Also, the Amazon rankings don't matter much in any country. It only indicates how well it's selling on Amazon, and isn't representative of the market as a whole. The simple fact that the 360 is above the PS3 in Japan should tell you that.