I found a seller in Singapore who is selling a black caviar classic flap silver hardware in Medium/ Large size. Her asking price is SG$1800. Do you think its worth the buy? She assure me its 100% authentic and I can bring the bag in to the chanel boutique in SIN to get it verify and check before making Full payment to her. Anyone know if the SA in SIN will do authentic check if I bring the bag in?