I'm just throwing this out from what I did.
As you may know I have built a piolethouse with 2 console's. There a 2 batteries in each console.
I spent over $300 just for battery cable and end's. 2/0 cable.
There are all kind's of diffrent system's on my boat. More than most for a 23ft boat. I spent aprox another $1200 on wire and end's. yes I have plenty left over, but I'm sure a job will come rolling in one day for me to use it.
This stuff was NOT bought at a box store. It was bought thru
Best Boat wire.
http://bestboatwire.com/catalog/default.php?cPath=23
It would have been 3 to 5 times more thru a box store.
One little neat tool I wiped out in an afternoon really help's
I wire each circuit right out of my head. Then I make a little sketch and go inside to the computer. I use a program called "Smart Draw 7" It's fun to play with.
Here's a couple of samples.
