Computer dealers are crowding shopping districts, and some analysts think the market is becoming saturated. In Connecticut alone, the two major shopping districts, Buckland and the Berlin Turnpike, for instance, shoppers can compare equipment and costs at Nobody Beats the Wiz, Lechmere, Circut City, Staples, and Office Max - all within minutes in one another. Yet, computer retailers insist that there has been a need for more stores - specifically their own - citing a nearly constant updating of equipment and a growing emphasis on service. T ....