I don't think the fender gripper mat will fit the Shaker 1000, since it doesn't mention it in the description. However, you
may be able to cut it to fit the sub in the trunk if you can find someone who knows what they're doing.
The difference in prices is due to the difference of composition in the materials. They are two completely different mats.
This one, which is the one I'm assuming you are talking about, is made out of PVC and nylon mesh. It is kind of a rubbery feeling material. The pony on the mat is probably just sprayed from a stencil from a machine.
This one, is the one that has the Shaker 1000 cut-out and it is carpeted with an embroidered tri-bar pony logo, which is why it is more expensive.
Hope that helps.
Also, I think this should be moved by a mod into the 'American Muscle' section.
__________________
"Money may not grow on trees, but it's planted in my Mustang." - 01FR500
"nobody gets ninjin that dont not need to be havin no ninjin too." - Zig
"Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind" - Dr. Seuss