So just how far away is the bus from you? The reason I ask is that it seems like it's very close to what you want but there's the rust issue and likely other "condition" questions lurking. I think it's one of those situations where you'd know for sure if you could just see the bus in person and get an overall feel for it. What's it look like in the engine compartment, what's the interior look like, what's the driver's area like, how are the tires, what's the underbody look like, just how bad is that rust in real life, etc?
I know it's tough to make the trip sometimes, I bought my first bus just east of Denver, CO and I live in NW Washington (nice 1600 mile test drive!
). I talked to the seller several times and felt I had a good sense of the guy selling the bus and we had a good rapport; he seemed to volunteer information about the bus (good and bad) without having to ask specific questions and seemed forthcoming. I took the chance that the bus was what he said it was and flew from Seattle to Denver where he picked me up. I was however, ready to leave the bus where it sat and fly home if it turned out to be a bad deal. It was actually better then he said, he was being conservative in his description. That was a very pleasant surprise and the bus drove home flawlessly, passed a DOT inspection with no trouble (not required, I just asked for it as it's a good way to assess the bus' condition), and has made many 1400 mile round trips to our vacation spot. So these situations can work out well in the end with a bit of work in the beginning.