No need for mobility? No need for a bus. Buy a RV with a bad engine etc. Cheap to buy for what you get and you don't need the crash worthiness of a Skoolie.
Former owner of a 1969 F600 Skoolie.
1998 Ford B700 Thomas body 65 passenger. 5.9 Cummins 12 valve with MT643 Transmission 123,000 miles.