Assume that any designer bag being sold at a flea market or street vendor is suspect. Designer labels do not authorize street vendors to sell designer bags or purses, period. It would be a rare occasional find to have a cheap designer bag being thrown out at a flea market; it's possible but improbable.

Be realistic about the price. Designer bags cost a lot of money because they are well crafted and they're status symbols. If the price is too good to be true, then it is, and the bag's a fake.

Know the signs of a fake or knockoff bag. There are numerous signs that can point to a bag's lack of authenticity:

1. The stitching: Look closely at the stitching of the bag. Sloppy, slanted, and uneven stitching is a sign of a poorly made, and therefore, fake bag. Designer bags will always have quality stitching because it is part of the designer's reputation to produce a quality item.

2. Check the tags or labels. Check the inside tags – are they stamped into leather or hand stitched? An obvious fake will have no name on the inside tag. Check outside tags as well because many designers include authenticity labels on the outside of the bag.

3. Check the material. If it's leather, it should smell like leather. If it's supposed to be durable canvas, it should be strong and well stitched. The material can tell you a lot about the bag's quality.

4.Check the logo. Logos are often a slip-up area for copies. They may have spelled the name slightly differently, such as Carter instead of Cartier. And, the more popular the "knocked off" bag, the greater the need to be careful because it's easy to be taken advantage of. When you look at the stitching on the sides and you see the "LV" it should be continued onto the other side of the bag and this also goes for the other symbols on the bag. And most knockoff Chanel bags have interlocking Os instead of Cs, which actually makes it legal to sell but is, of course, a fake. They snip it to make it look real when it comes out of a dust bag.

5. Look for a serial number. This is a stamp inside that says the brand (it may not be in all bags).

6. Check the lining. If the interior sounds like paper rubbing together, then it's not the real thing. A real designer bag will be lined, and often with leather. Again, check the stitching of the lining if relevant.

7. Look for color variations. Although some variations will be blatant, others may be very subtle. Be sure to have a close inspection.

8. Notice wear break-in. Although this is post-purchase, how your bag wears in can be a sign of its authenticity. For example, the leather on the handle, after a few weeks, should look like a good worn leather jacket does. It should have an "aged look". Stitching should stay intact and not begin to fray.

Source:Wiki answers