First of all, Balenciaga doesn't make enough handbags to go around at the retail price to begin with.  The medium motorcycle sells for $1099.00, the small classic for $999.00.  No less.

All new 2005-06 and 07 handbags have brass hardware and raised cursive lampo zippers.  If you see a new with tags handbag with silver hardware its not authentic.  If you see a BIN price less than 900.00 - either something is wrong with it, i.e. dirt spots, stains, tears, etc. it's likely not authentic.  The fakes now have the cursive lampo zippers so even that is not a guarantee that a particular handbag is authentic.

Balenciaga releases a half a dozen or so colors each quarter.  Familiarize yourself with the colors to make sure you are considering an authentic balenciaga.  See refernece below.

Of course make sure your seller has postive feedback and no negative marks for fake merchandise.  Also be sure to pay with paypal so you have some recourse.  Be sure to ask the seller where they purchased the item.  If they say they get them wholesale or some supplier in Italy, its not likely.  Balenicaga tightly controls their inventory. They allow no shopping cart style websites - a few authentic sites will require you call and place your order.  If in doubt call Balenciaga NY (212)206-0872 and ask them if it is a legitimate retailer. 

In closing I would like to say that eBay is great place to shop and buy a USED Balenciaga handbag in a color no longer produced.  Its not likely someone has stashed a NWT indigo or turquoise Balenciaga Handbag and is now selling it new.  eBay is also a great place to buy a Balenciaga sold out color.  Bear in mind you will pay above retail for this privilege.

And finally, if its too good to be true, it probably is fake.

The Clothing and Accessory Community Board has information and are often willing to help.

Go here to learn more:

forum.purseblog.com/balenciaga-reference-library/