I'm seeking advice on how to go about tethering any of the currently sub $200 camera drones out there, or alternatively how to do the same with a home build one on something like ardupilot.
The objective is to have all radio communications over wire, in this case that would be control signals up and video feed back down. I do not need power to be over wire, though that would be nice (and that's actually been covered elsewhere before).
Not possible with the toy drones you specify. Why would you need to do this any way. Existing transmitters for video are dirt cheap for the short ranges you are talking about. If you want a secure info system tethered there are companies who have done this for military stuff. $200 dollar drone and secure link? I think you must be up to no good and don't want to get caught.