I used Kakaku.com's web site to get an idea of the price. The digital camera page should be okay to navigate without Japanese knowledge.
The link will take you to a list of manufacturers in alphabetical order. Click on the brand you are interested, and it will list all models that company makes. Click on the model you are interested, and the page will change to the detail view. In the detail view, the bold red number is the lowest price, and the small black number is the average price. Scroll down a little more to the radial diagram, that is the user feedback for that camera. The line chart below is the price history: the red line indicates the lowest price and the blue line is the average price.
The table below the price history is a list of stores the web site sampled for price information ordered by the lowest price first. The column shaded in red is the price. The store name and phone number are in seventh and eighth column respectively. The store name is a link to store's information page with policies and map (via a link).
This web site gives you the best prices usually offered by stores on the back streets of Akihabara. I used this method to buy my camera last time. Let's say this time I am interested in a Fujifilm F10, I would click on Fujifilm on the first page, and scroll down and click on FinePix F10 on the second page. I can see the lowest price right now is 37,200 yen offered by PC Bomber which has it in stock. If I feel PC Bomber is too much of a hike from JR Akihabara station, I could opt for DigiPlaza at the same price.
The larger stores like Yodobashi Camera and Bic Camera have more or less the same prices. They compete on customer loyalty point cards. Normally you earn between 5% and 15% for each product purchase. When something is on sale, the price is not lower, but the points you earn is higher. If you are going to shop there, first apply for a point card, make the largest purchase and spend the points on accessories and smaller items.