Something to consider. I'm always nervous about something someone wants to trade. I usually see that as a sign that they can't sell it very easily or it's not worth the same as what you have. The other thing that would make me nervous is that he hasn't owned it very long. I'm not saying it's not done right or he's shady or anything, but it may not be the most user friendly vehicle to own & the novelty wears off quickly. Roller coasters might be fun, but no one wants to ride one for an hour at a time.
It does look cool though!!