No I am not a shop, nor do I own one any longer.
I am retired from ASE and ATRA (Automatic Transmission Rebuilers Association) and owned an auto repair business in Cal and before that a service writer/forman/exotic trans builder for a national trans chain.
My Nephew will put it in himself with a little supervision just so he doesn't pinch a wire or something.:-)
He works in a custom fab shop for Dodge trucks and is very capable, but he thought he would just have someone elso do it so he didn't have to mess with it on his day off.
For $1,100.00 he'll mess with it. :-)
There was no written estimate, as he just asked if they would change it and they told him they would do it for that price.
Very likely just trying to get him to go away, since he already had his own parts.