If you accept the 'average' price of a bus at $2-3000, then you can go from there.
You won't have to paint.......how much is that worth?
How are the tires? New ones all around will be $1500 and up.
114K is fairly low miles......might be worth another $1000 or so.
Any rust issues? Lot of time, hassle, and money may be involved.
2 new Group 31s will cost $300 or thereabouts.
How's the suspension/overall ride comfort? Tight steering, or loose? Any clunking or wandering? Take it for a ride and listen to what your butt tells you.
I do like the short transit-types, and those windows are more desired by most than standard bus windows.