I think this one that Jumpman found looks to be better than most in this price range. I am sure there is some wiggle room built in.
Below is what we are talking about for the archives:1956 GM PD4104 Bus Conversion - $5000 (Franklin TN)
Bonnie is a 1956 PD4104 GM bus which I converted in the middle 1980ís so we could take our five kids and go camping. She was designed with space efficiency in mind.
She has a 17 Gal electric water heater, 100 fresh and 100 holding tanks, a 5 KW Onan Generator, 2 13.5 roof airs, a 4 burner stove with oven, and a Norcold refrigerator
The bunk area opposite the Bath is modular and can be removed to put in additional closets or a computer room or whatever.
The back room has foton bedding. Each side opens partially for a BIG twin or fully for a bigger than King. There is also a place for a post table in the back room so the kids could play a game on a table while traveling.
The 671 Detroit was rebuilt in 1994 in New Jersey by the Detroit - Allison dealership. Since then she has had about 60,000 miles put on her.
I had Shepherd power steering installed in 1995 ( the smartest thing I ever did).
I built a 1990 Eagle Bus and put in 2 slide outs which I began using in 2006. Bonnie Blue 1 has been sitting since then. She will need new batteries and I would put on new tires as they have been sitting. They hold air but The should be changed out.
Call Bill @ 615 394 5911 for additional details.