I cant see why this should end up ugly and what firearms has to do with the OP post. Is it the state of mind in US? Its an ethical dilemma, even though nobody knows how destitude the seller was. But ten bucks means survival for some, and if survival is the key thing for humans, he did OK (or not, kinda cheap actually...). The buyer is the real problem, taking advantage of the situation.

I side with mazdaspeed, buy the bike and hand it over to the police. Might just end up at the right owner. And maybe thats what the buyer intended to do. After strippin´ it...