All things mobile in Japan
In the UK the Nexus 4 is sold by Argos.co.uk at some MAD markup on the Google Play price - about 50% more than the device was selling on Google Play IIRC. Doesn't surprise me that the Yodobashi price is that high - if it does sell on Google Play, I suspect it will be at a more reasonable price.
I honestly don't understand Google's distribution methods sometimes, especially in regards to the Nexus family. Some stuff like the N7 gets sold everywhere, while the N10 hardly gets any, and the N4 gets released almost a year afterwards.