I had a good shop install my remote 3 months ago. I now decided to add DM. The office manager/receptionist asked the tech. Came back and told me the hardware and labor would be $100 since most of the work (the remote) was already done. She must have misunderstood the tech? I understand that 98% or the work is already done, but even on Amazon the 5400 is $150, unless there's some more basic unit? $100 for parts and labor can't be right, can it?