I'm personally not opening that zip file, the forum has sort of made me paranoid of certain stuff, but if anyone feels like checking the conversations and the user did, as it looks like, scam for 15$, you could create a type 3 flag.

That particular user does already have one and a -4 negative trust... I'm not going to say that it was your fault that you got scammed, because it's the scammers' fault, but in the future, even when dealing with small amounts, do all your due diligences and at least check the users' trust feedback. Other flags may go unnoticed by new members, but at least the feedback is pretty straightforward