Ok, this story is old news but in case you missed it:
LVMH, owner of the Fendi brand sued Wal-Mart in June for selling fake Fendi handbags, wallets and key chains in Wal-Mart owned Sam’s Club stores.
“The company cited one example of a Sam’s Club store in Las Vegas selling one of its handbags for $295.03 (£160) compared with the recommended retail price of $925.” read more.

Although mums and dads selling fakes is a widespread problem on ebay, it also goes on relatively unnoticed in shops and now apparently, in corporations.
One Tool I use to question if the supplier I’m working with is legitimite is Rip Off Report.
If your supplier has been in business long enough to rack up some complaints, you can generally find them on there.

