Help me decide on a bus

[Stephen g]

I found a bus in Arizona. I live in Washington state but dont mind the trip for a rust free bus. It's exactly what I want has all the doors and seems to be in good shape. It is a 2000 Ford e450 cutaway school bus. It was 307,000 miles on a 7.3 diesel. Is that too many miles to purchase? I don't plan on putting more than 10,000 miles per year on it and think I am ok with replacing the transmission in a few years. I just need some advice on whether I should take a shot on my dream bus. They are asking $4900 i want to bring it down to around $3500 and they said the price is negotiable.