Wiring kits?

I was trained in electronics in the Navy 37 years ago and kept doing that in the space program after. About 1997 my boss asked me to switch to electrical fab (cables mostly) to support the space station build. Lot of building harnesses on form boards since. One day I'm going to do one for my own car. Comparatively will be a piece of cake. But considering even cheap parts and labor I can see how the price gets up there for quality custom stuff. But with my background I won't pay it.