New to the site and here to ask a question.

[Gunsmith63]

I decided to install ghost lights in the door panels.Yeah, like a newbie, I didn't disconnect the battery. Now the map lights, head unit, climate controls and key lock don't work. The dealer sm says the body integrated unit is fried and I'll need a new one. $350. also the keys will need to be re coded $100. each. By the time he was finished, the price was up to $700.
Can't I buy a biu and install it myself? I found one from a dealer for $250. and do the keys really need to be re coded?
I think my dealer is pulling my leg.
Thanks in advance for any help.