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.
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.
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.