We may not know what we don't know, but from the OP, we can surmise that the client did not spend a whole lot of money on this.
11 X 70v VC's could have been only a few hundred dollars, add some basic 70v amplifier and some wire and you are not talking about much of an investment here.
To take that and hit him with 13k "to do it right" I bet would get his jaw to drop to the floor pretty quick. Keeping in mind he also has other amps connected to other areas in a similar fashion (at least that's what I think I read in another post)