crutchfield's prices are the same as retail stores such as cartoys, goodguys, and magnolia hi-fi etc.
but they give you a wiring harness for free, its 20 bucks if you buy it from a retail store. if you have never installed car audio before, crutchfield is very newbie friendly with their customs instructions. they have good customer service.
then again, you get free installation in a retail store, but you would have to pay for the harness. so pick your poison