[Nyororin]

Depending on the model, usually between 40000 around 50000 yen new in the shop.

However, I can`t really recommend buying one in Japan to use elsewhere. No, make that I can`t understand the point...
All the services are unique to the phone carrier, so at the best the only thing you`d be able to do is use the lower quality calling features and the camera. Text messaging supposedly uses a different format, as does access to the net via your phone... So it would be a real waste just to get a Japanese cell phone and lack the ability to do pretty much anything with it.