The ground instructors aren't flight qualified and don't make the same. The only guys I know do 757 recurrent. They have been there a long time and are good at what they do. Sim instructors are called flight qualified supervisors. They are management and not part of the pilot group or the union. It used to be, back in the day, they made UPS Capts pay plus stock and management retirement. They did quite well. Last ten years or so I've heard UPS makes a deal with each guy. I've heard no pension and pay more in line with senior F/O's. All with no work rules outside FAR's and no union contract for protection. There have been guys who actually quit. That was unheard of back in the day.
As a flight qualified supervisor, you're not necessarily guaranteed to be a sim instructor or have any choice of location. You could get sent to Anchorage or be the new Rockford ACP.
To answer your questions. I'd say a starting fqs would be between 150 and 200K. Maybe 80K for a ground instructor (total guess).