Some models only require the ipd ribbon to be replaced. Not the 15’ models :( doubt its any cheaper to try first though. Nothing else thats a top case replacement/ that you should take in to a genius bar/ and say you have some keys not functioning at random. Heads up Apple may charge at least 400.
open up the bottom case and try another magsafe/ I’ve ran thru 2 new ones before the light illuminates again/ also may need a new MOTHERBOARD and RIO BOARD. Hopefully only a MOBO