After a bit of research to determine what we needed and wanted (Requirements versus desirements ;) ), we found what we were looking for on Craigs List. I did have to go 3 states away to find the one I wanted.
My requirements:
1. Wheelchair lift toward the front
2. Pre emissions
Desirement
3. Flat-front diesel pusher (either a Carpenter or AmTran with either a Cummins or DT466)
As a professional truck driver, a conventional bus is just another truck to me. I wanted something more challenging/fun to drive
And I didn't want to have to deal with a dog house.
Best resource is *this* web site. Read all you can and learn all you can and it will help you develop an acquisition plan ("Requirements/Desirements").
Whether its a school bus, transit bus, shuttle bus, coach .... you can generally find what you are after in the online classifieds. I did. Be advised, though, you may have to travel to bring it home.
You can try the auctions (as stated above) and get some awesome deals .... IF you know exactly what you are bidding on. But the school bus auctions are a gamble, especially if you can't preview the lots (check to see if it even runs....) or even get told what the actual condition of the vehicle is. For work a year back, we bought a school bus (2004 or 5 IC conventional) at auction for about $350. Beautiful condition. Even drove it back to the shop .... but the transmission (MD3060) wouldn't go past 3rd gear (that fix is hard and expensive) but it was okay as we only wanted it for parts for one of our dump trucks. And some of the non mechanical parts even cross fit to my RE3000
I asked the Boss about the beautiful set of Alcoa wheels. He picked up a hammer ....
Good luck!