There are many other sound dampeners out there. I have seen RAAMAT reccomended on some fourms over and over again because of its price and quality. Fatmat is also inexpensive, but I have never used either of them so i could not tell you how they would do.
EternalDesigns has $1 / Sq Ft [ 40-45mils thickness ] $2 / Sq Ft [ 80-85mils Thickness; I have this, works very well ] $3-4 / Sq Ft [ 90 ? or 100 ? mils Thickness ]
85mils cost me $120 for the whole car outfitted. Not every single spot but most important spots where road / other noises come in significantly