How Do High Street Consumer Electronics Stores, Such as Dixons or Tandy add Value to the Products that They Sell?

A high B grade almost A...how annoying!! Perfect in every way!!
How do Dixons and Tandy add value to the products that they sell, and, in doing so, what benefits are passed on to the consumer? Do high street consumer electronics stores offer better value for money than their mail-order counterparts?
The raw price figures show that, obviously, the high street stores cost more than the mail-order stores, but are the benefits that the high street stores bring worth the extra price?
I took the prices of five types of products, a large stereo, a portable system, a small television, a video recorder, and a computer. The large stereo was an AIWA NSX-V710, the portable system was a Sanyo MCD 278, the small televisions that I chose were not available in both stores, and so I had to choose similar models. The models I chose were the Matsui 14' Remote from Tandy and the Nokia 14' Remote from Dixons. The models were both available from the mail-order supplier, at the same price. The video recorder that I chose to use was an AKAI VSG745, and was in fact available from both stores. The computer was the most difficult part of the system to match, as the Dixons systems came with some added bonuses such as extra multimedia software and Internet capability. …