i guess the only real reason to buy one of these is if you dont feel like removign the motor mounts to put in urethane inserts or new mounts all together. but like ^ said, there over priced compared to what u could do.
if you have 15 bux you could just fill your stock mounts with 3M liquid window weld. i plan on doing it for my mounts. heres a link to HMT, they gave a pretty decent write up
http://www.homemadeturbo.com/tech_projects/poly_mounts/