Many people talk about the Akihabara neighborhood of Tokyo as "the place" to buy electronic goods, but this is overrated. If you go to Akihabara, you will just exit the train station and be assaulted with dozens (hundreds?) of small little shops that will try to sell you an array of products. The only reason to go here might be if you know a specific product, and print out a description of it and carry that around with you. An merchant will show you the price, and then will show you the tax you will pay on top of that. In this case the price does not include the tax (like in restaurants and at hotels). The prices are not cheaper than advertised elsewhere. For a quick look at variety, you are better to just pop into a large electronics store wherever you might find one on your shopping around Japan.