With enough customer motivation I don't think price would be an issue, but I don't think he would be in the mood for $5K. In-ceiling drop down would involve major construction because it's an old house, corner location in the room, there is a room above, it's an outside wall, and there is about 2" total vertical clearance with the TV in viewing position. (Plaster on wooden lath construction)
One possibility might be using shelf slides. Essentially, there would be a pull-out shelf pinned to the ceiling behind the TV and the TV would be mounted to a post attached to the "shelf". We only need a few inches of movement.
---
In many respects this is a grotesque installation with roots in 1990's. There is a den behind the TV location with a wall of VCR's, audio cassettes, DVD's, DVD/VCR's, video modulators, and a B&O 5000 system. I wouldn't be shocked to find a Laserdisc player buried somewhere. It's mostly composite video. Somehow, he can operate all of this. I don't want to touch anything on that wall. There are little alcoves of equipment stuffed in closets all over the place. (Remember B&O Master Link from that era?) And, of course, he wants to view his video library on that nice, new 4K set. The modulators take care of most of this, but there is a VCR/DVD in the bedroom. The control system is a combination of Master Link, Radio Shack's version of BSR X-10, and native remotes (with IR extenders) everywhere.
