I just bought a Red top at Walmart for $148.99 Canadian, I thought that was rather cheap. I'm not sure if that was a sale or regular.

 

Optima is not that great of a battery but people buy them
I have my daily driver which is a Honda with its tinny little battery running the whole car and the system with no dimming nor do i have any engine whines. I also have everything stock in the car but i just added a couple of extra grounds thats all works fine

 

how many watts is your system? how big is your alternator?

 

Call me what you will, I've got a 34 yellow top in my 1995 Grand Prix and on a really cold morning started my car better than a 2005 Corolla. I've also had it a few years and have no complaints. I also picked up a 1 or 2 amp trickle charger for just over 20bux, just in case. As long as the car is running, it's the alternator that does the grunt work.