There is a common story spread around the internet that you can not visit the national parks with a vehicle over 30' long. I found a couple that did great research on this, and what they found is that there are some campgrounds that have shorter requirements, but the parks allow vehicles 40' or more. The longest school bus is 40'. So while there are campgrounds you can't visit, you aren't barred from the parks.
We have seen many customers sacrifice size or comfort, just to fit this 30' requirement. And in today's market, the smaller buses have nearly doubled in price. The full size buses haven't seen nearly as much price increase.
Most school districts in America do not run small buses. I don't think I've seen 5 small buses in Florida in my whole life. Do they run small buses in your town? Usually you have to find the large cities, that are usually in the rust belt, to find small buses in quantity. Of course everyone wants a rust free, southern school bus.
Visit the Roving Foley's research here National Park Length Restrictions