Help in authenticating Balenciaga Motorcycle bag

HI,

I am not a fan of designer bags so I dont have any idea or care if they are fake or not. But I happened to drop by a local surplus store and I spotted on a Balenciaga Motorcycle bag. I bought it 1/10th of the original price, but then again, 1/10th of it is a big money. Until I read a forum somewhere on how to spot a fake and a real one. And I got disappointed when I found one point is not present in the bag. But I need opinions of the experts please. Hope you can throw me your two cents.