As said, dealers are expensive and the smaller shops work by the hour. You ask him a question, he stops work to answer, you're still paying. Just like a plumber, he's on your time(money).
I read from your post, you are the mechanical one of the family. Bear with your parents, they are thinking of you and your safety, I know, I'm talking like a parent, I am.
What would be nice is to do some research from the library and maybe from the dealer on the electrical system, like copies of the schematics, etc.
An idea or two, Do you have a friend whose parent is a auto hobbist or mechanic your parents would trust? Can you talk to the Chevy dealer? What I'm suggesting is BARTER!
Trade your labor, sweeping, cleaning, either the shop, cars, etc., errand running, filing,
any little job you could do to decrease your cost.
If you do a sell job on yourself, you might get some help, but don't be a whiney kid about it, be respectfull and state your case with a straight face and look people in the face when you talk to them.
I better stop now, I could write a book, probably have already,