Electronic prices in Akihabara/Japan

I want to ask if prices of electronics in japan or akihabara are bigger or smaller than europe. Prices of cameras/PC game/laptop/video camera/cellphones.. etc.

Almost impossible to answer in a few paragraphs as it depends against which country in Europe you are comparing prices. VAT alone can change prices by around 10% between EU states and it would also depend on exchange rates with the relevent currency of each EU country and the Japanese Yen.

Also, if you are actually planning to buy some or all of these items, you should be aware that product guarantees would often only cover Japan, not worldwide. Most available laptops would offer Japanese operating systems and keyboards, PC games would also be in Japanese. As I understand it, mobile phones are not sold to overseas visitors, you can only rent them. Finally, Japanese video cameras operate on the NTSC system and most of Europe uses the PAL system,which will effect playback. Depending on your TV, it could be anything from an OK image to just static on playback.

I guess the only things that are worthwhile to buy are camera's. In general the types they sell in Japan (for the Japanese home market) are the same as the ones worldwide. But as said above the warranty is only limited to Japan so here you run a risk. The Japanese manual is not a big problem as you now can download a manual in your only language quite easily. You have to check though that the camera menu can be changed to a language you can use.
Keep in mind that if you go to the taxfree shops in Akihabara and you go to the floors for the overseas market you will find (at least that is my feeling) that everything is quit expensive. (You can better buy stuff in some of the larger electronic/camera shops).
However it is fun to wander through the backstreets of Akihabara or the building with several floors with small stands/stalls with numerous articles and where they also have second hand shops and there you might find something interesting and inexpensive.