I buy lots of DVD's off EBAY and I have had the misfortune of purchasing the odd fake one!
From the experience that I have had over the past year I am going to give you tips on spotting untrustworthy sellers
This can also be applied to buying CDs.
Always check the feedback as people usually leave neutral or negative feedback expressing their disapointment! Although don't judge a seller for a feedback score of slightly below 100% as it doesn't necessarily mean that they are selling fakes
Alot of sellers in the description say that they are sending the DVD in a plastic wallet to .. "save postage". This is usually a sign that it is a fake especially if there is no artwork to come with it! It is just an easier way for the seller to sell these fakes with little effort!
Make sure that the picture is of the item especially if the seller has a bad rating.
If the price is ridiculously low then you may think it is a bargain however this usually a sign that the disc may be a copy so it is usually worth paying slightly more so that you are not disapointed.
If you use a mixture of all the hints that I have given then you should be able to avoid buying fake DVDs and CDs.
Make sure that if you have bought a fake that you leave feedback that reflects this so that others will not be disapointed.