$85 + shipping??? damn… I think I paid $50 with shipping for mine; but then again that was 2 years ago.
Actually he’s using it for a primary fuse instead of using a fuse.
It’s not a bad idea with the amount of current in the primary wires for large stereos; as long as all the sub-components are fused as well, having a CB in the main is ok.
If the CB is the only thing fusing the amp(s) then I say no-way; the reaction time of a CB is slower than a fuse and typically will allow damage to occour to the component. If it’s just for the main-line then it’s only protecting a large over-current in the wire to prevent it from starting fire and burning the car; then the slower reaction time is ok.