How much are they charging you? Wiring doesn't take a rocket scientist, quite easy. Just takes time and effort. You can use the left over wires for big 3 upgrade. The tricky part will be the end connectors.
I have no idea how much it is, Tuan couldn't give me a quote even though i explained exactly what i needed done - whatever. Yes, wiring is easy and i know exactly where everything goes, but what i don't know how to do is take my car apart. I also don't really have tools.
On 2nd thought...there's a kid in my building that DOES know how to take the car apart, i'll ask him and maybe we can work together. I really doubt even together we'll be able to do the big 3 though.
Big 3 is like any other wiring. The alternator to battery will however take a bit more effort cause it goes through hoses and engine parts. What I didn't see on your list were the end connectors. Big 3 requires them, especially the alternator to battery. If you don't have them, you can buy the connectors. It might be easier for you if you purchases 12" - 24" of 2/0 gauge wire with the ends. When someone doesn't give you a quote/price, it means they're either not sure how to do it, or will charge you $100/hr or more.
I don't doubt their competence, I heard good things about that place. As for paying a lot, that may be the case. Now, how about you baby me through this and give me the link with that wire that has those connectors? THX Isaac, you're the best!