"There is no cable!"
Yep, definitely don't go to that guy.
On those systems (and the 2011 models) with a funky hard drive, that's one of the first things we check. Basically, put in a new drive and format it. If it takes 30 seconds, the cable is fine. If it takes 10 minutes or longer? The cable is bad (or it's a bad board, but that's rare).
And $135!
Dang, that's a lot for a $20 part and ten minutes work.