Sound dampening.

Im planning on applying some sound damnpening sheets in my car.Basically,im asking around if anyone else has had it done,and what was the cost.I dont want it super fancy,just something that blocks out most of the noise.Ive seen "Dynamat" and it works pretty well from what im told.But its really pricey,and they get you with all the add-ons.So,does anyone have any suggestions,but that are not as costly?