hard telling. They could show you a pic of a real bag, and send you a knock off. Go to LV's website for tips on not getting ripped off before you buy a questionable bag. Buy from places like ebay, if you're looking for a deal. They have special things in place to protect you from getting ripped off.
I found a real (proven) D&B bag for $3 once because the person thought it was a fake.... that was one of the best shopping days of my life. I've also found really good fakes (mainly coach) where everything is perfectly spot on except for a zipper pull, or the thread color is dk brown and its supposed to be med. brown.