a much easier and simple solution- read their feedback.
I dont know why people would send someone $500+ they've never met and has 0 trader feedback, its almost a begging to be scammed.
I buy from upstanding members only, and if no one has what I need, I buy from a retailer.
"Whoever appeals to the law against his fellow man is either a fool or a coward. Whoever cannot take care of himself without that law is both. For a wounded man shall say to his assailant,'If I live, I will kill you. If I die, you are forgiven. Such is the rule of honor."