The only way to go :

Product Prices | Sound Deadener Showdown

Don is a GREAT guy, and he actually knows his stuff. Not just sales. He knows the science behind the soundproofing. Plus, he doesn't do the typical "just put on layers" of really high priced product. I am actually very happy that he upgraded his webpage where he lays out the information. There are other links where he did a price comparison and breakdown of the 5 or 6 players in the car sound proofing business. VERY VERY professional and incredibly informative and it shows how much marketing gets involved with this aspect of automotive upgrades.

I am shooting to do the entire car before it gets brutally hot in sunny South Carolina.