I would think the $5000 is just what you said-bait on the hook. I was in my RV today andlooked at the drop bed over the front seats. You would have to gut what ever cabinets and what ever else is in the cab area. It would be a big job and you may (will) never get it back on resale.
Mine has a rack system and an electric motor to drive the bed. If you PM me I will be happy to send you pictures. If you have a Fleetwood dealer in your area stop in. They should have one on the lot with a cab bunk. The Thor ACE has a over head bunk also.