Whee, that is seriously steep for something that rough.
I would pass in a heartbeat.
Now, I may get flamed for this, but here it goes. Make sure you know what you are getting into with the bus. If you can do mechanical work yourself, it might work out well. However, things add up very quickly. Just as an example, we have to replace our air compressor this trip. The compressor itself is $500 (rebuilt) and Clark Power charges $110 an hour for install..... In my opinion, what you pay for the bus is often the down payment, in a sense. Be prepared for the costs afterwards.
FWIW
John