I can't opine as to the total cost, but I'd be mad about the wires. High quality wires do NOT wear out!! And if the wires were OE, they were high quality I'm certain. I suppose if they make the arguement that one or more of the resistor ends was bad, then it'd be cheaper to swap them out than diagnose the bad one; true enough, but I'd want to at least hear their contention.
As to the lack of an estimate up front, I'd only get mad if you didn't trust them. For example, imagine I gave my car to Benzmac...and he gives me a bill for $2k. I pay it. I thank Benzmac for his fabulous service, and I drive away knowing a pro has been over my car. However, if the same thing happened somewhere else, I'd want to talk to the tech.
I'll let the pros take it from here...but $1,400 seems a little high.