I know where to find them, in fact, they had three the last time I was there... (a month ago)
But it's in Japan.
Fujiya Camera is located At Nakano station (take the Chuo Local or the Chuo Express from Shinjuku Station in Tokyo). It's about four stops on the local, it's the next on the Express.
Jump off and I think it's the north exit from memory... Basically when you get down stairs, there are two exits, one goes straight out, the other you go around a bend where the checking gates are. Turn right after the ticket gates, and you'll see what looks like a mall. Go through, and turn right down the first alley. At the entrance of the alley is a fish store (on the left of the alley) and on the right is a store selling those Octopus balls. Head down there, keeping an eye on the left for a store with a big yellow shopfront. Lots of camera posters there, but they have loads of stuff.
If you're not going or even live there, see if you know someone who is going over there. From memory the weren't cheap, but not all that expensive either.