Japan has two kinds of electronics products (mass market) - one for domestic market and another for International markets. The Japanese voltage is a strange 100V (not 110). So generally hard to find a transformer. The costs are cheaper for domestic versions, but you may find no warranty outside or menus in Japanese, so be careful.
The costs of some mass market stuff like high end TV's and DSLR's are cheaper than in other markets.
Places like Akhiabara, you will get lost with options, but may not find anything significant. Do your search for exact shops and then go to these places, to make it more useful.