hmm.. I think you also have to look out for the delivery and installation fee. Many places advertise incredibly low price, but when you are there, they tell you other hidden cost. And the whole thing ends up even more expensive. To avoid making a waste trip, call up to ask for the actual prices and cost involved.
Many places sells the same thing but some places sells it higher priced, some places lower. A better way to compare price/quality would be to do a google search, and read the reviews of people who have bought it. Consumers don't lie.