I'll agree with the fact you should be careful. A normal person would not do a lot of what this guy is doing. It's a shame we have to think so critically about it; darn those scammers!!!

That all being said, it isn't a bad thing to talk to him. Maybe there are reasons why he wants to do it this way. I am fairly impetuous and have been known to make decisions that might seem strange to others. This guy could have viewed your history and seen that you are a straight forward person and that this bike is a good deal. Maybe he had been thinking about getting one and this one seems perfect. Just make sure he has no more info on you than he has to have, that you aren't at risk at any way, and that you aren't scammed.

Despite the fact I can see reasons behind some of his actions, it really doesn't add up. Stand firm and definitely question what's going on.