Unfortunately you are going to find these anywhere you go. There is a big market for knockoffs with flea market sellers so we will even list them as suppliers. You just need to do your research on the suppliers. And of course use common sense. If you think its a knockoff your pretty guaranteed it is.
As far as dvds, I dont put much into them anymore. So many fakes on places like ebay, And wal mart selling them so cheap they are not worth the trouble.
If you want guaranteed Authentic products then you really should go with retail liquidations. I sell nothing but authentic products. I never worry about them because I am buying them directly from a Retailer. Ebay has never been concerned with my auctions because they know I am a Authorized Broker for several retailers. Anyways the profit margins on Retail liquidations is so much higher then any other source.