Here the pictures show the units. Here hopefully the first picture shows the unit you posted. There is a bunch wire already there, so if you must have the unit you probably need to figure out about the wiring.
Another picture here shows there is another box that the sound box connects to, and yet more wiring, and I am not sure what it does
. I guess it never hurts to find out what the installation cost would be in its entirety, if it includes more than the box.
Good luck and cheers~